The COVID-19 pandemic triggered a surge in demand for facemasks to protect against disease transmission. In response to shortages, many public health authorities have recommended homemade masks as acceptable alternatives to surgical masks and N95 respirators. Although mask wearing is intended, in part, to protect others from exhaled, virus-containing particles, few studies have examined particle emission by mask-wearers into the surrounding air. Here, we measured outward emissions of micron-scale aerosol particles by healthy humans performing various expiratory activities while wearing different types of medical-grade or homemade masks. Both surgical masks and unvented KN95 respirators, even without fit-testing, reduce the outward particle emission rates by 90% and 74% on average during speaking and coughing, respectively, compared to wearing no mask, corroborating their effectiveness at reducing outward emission. These masks similarly decreased the outward particle emission of a coughing superemitter, who for unclear reasons emitted up to two orders of magnitude more expiratory particles via coughing than average. In contrast, shedding of non-expiratory micron-scale particulates from friable cellulosic fibers in homemade cotton-fabric masks confounded explicit determination of their efficacy at reducing expiratory particle emission. Audio analysis of the speech and coughing intensity confirmed that people speak more loudly, but do not cough more loudly, when wearing a mask. Further work is needed to establish the efficacy of cloth masks at blocking expiratory particles for speech and coughing at varied intensity and to assess whether virus-contaminated fabrics can generate aerosolized fomites, but the results strongly corroborate the efficacy of medical-grade masks and highlight the importance of regular washing of homemade masks.

Background: The pandemic of COVID-19 is growing, and a shortage of masks and respirators has been reported globally. Policies of health organizations for healthcare workers are inconsistent, with a change in policy in the US for universal face mask use. The aim of this study was to review the evidence around the efficacy of masks and respirators for healthcare workers, sick patients and the general public.

Methods: A systematic review of randomized controlled clinical trials on use of respiratory protection by healthcare workers, sick patients and community members was conducted. Articles were searched on Medline and Embase using key search terms.

Results: A total of 19 randomised controlled trials were included in this study - 8 in community settings, 6 in healthcare settings and 5 as source control. Most of these randomised controlled trials used different interventions and outcome measures. In the community, masks appeared to be effective with and without hand hygiene, and both together are more protective. Randomised controlled trials in health care workers showed that respirators, if worn continually during a shift, were effective but not if worn intermittently. Medical masks were not effective, and cloth masks even less effective. When used by sick patients randomised controlled trials suggested protection of well contacts.

Conclusion: The study suggests that community mask use by well people could be beneficial, particularly for COVID-19, where transmission may be pre-symptomatic. The studies of masks as source control also suggest a benefit, and may be important during the COVID-19 pandemic in universal community face mask use as well as in health care settings. Trials in healthcare workers support the use of respirators continuously during a shift. This may prevent health worker infections and deaths from COVID-19, as aerosolisation in the hospital setting has been documented.

Keywords: COVID19; Coronavirus; Coronavirus disease; Mask; Personal protective equipment; Respirators.

Cervical spine immobilization devices are widely used to stabilize the cervical spine and prevent neurologic deficits associated with unstable fractures. In order to quantitate their efficacy we measured controlled cervical spine motion in three axes, using six different immobilization methods in 25 volunteers instructed to actively move their necks as much as possible in the directions of flexion, extension, rotation, and lateral bending while lying supine. Control measurements were made with no device and measurements were repeated following immobilization with: soft collar (SC), hard collar (HC), extrication collar (EC), Philadelphia collar (PC), bilateral sandbags joined with 3-inch cloth tape across the forehead (ST), and the combination of sandbags, tape, and the Philadelphia collar (ST/PC). Neck movements were reported in degrees recorded on a hand-held goniometer. There were no significant differences between control and SC measurements except in rotary movement. PC was not significantly better than the other two types of hard collars, except in limiting extension. ST immobilization was significantly better than any of the other four methods used alone, for all four movements. The addition of PC to ST was significantly more effective in reducing extension only.

BACKGROUND

Admission to intensive care unit rooms previously occupied by carriers of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enteroccoci (VRE) had been found to confer a 40% increased risk of acquisition, presumably through environmental contamination. Subsequently, a cleaning intervention was shown to reduce MRSA and VRE room contamination. We now evaluate the effect of this intervention on the risk of acquiring MRSA and VRE from prior room occupants.

METHODS

We conducted a retrospective cohort study of patients admitted to 10 intensive care units at a 750-bed academic medical center during the enhanced cleaning intervention (from September 1, 2006, through April 30, 2008; n = 9449) vs baseline (from September 1, 2003, through April 30, 2005; n = 8203) periods. The intervention consisted of targeted feedback using a black-light marker, cleaning cloths saturated with disinfectant via bucket immersion, and increased education regarding the importance of repeated bucket immersion during cleaning. Intensive care units included medical, cardiac, burn/trauma, general surgery, cardiac surgery, thoracic surgery, and neurosurgery units. We calculated the number of room stays involving the potential for MRSA and VRE acquisition and then assessed the frequency at which eligible patients were exposed to rooms in which the prior occupants had MRSA-positive or VRE-positive status.

RESULTS

Acquisition of MRSA and VRE was lowered from 3.0% to 1.5% for MRSA and from 3.0% to 2.2% for VRE (P < .001 for both). Patients in rooms previously occupied by MRSA carriers had an increased risk of acquisition during the baseline (3.9% vs 2.9%, P = .03) but not the intervention (1.5% vs 1.5%, P = .79) period. In contrast, patients in rooms previously occupied by VRE carriers had an increased risk of acquisition during the baseline (4.5% vs 2.8%, P = .001) and intervention (3.5% vs 2.0%, P < .001) periods.

CONCLUSIONS

Enhanced intensive care unit cleaning using the intervention methods may reduce MRSA and VRE transmission. It may also eliminate the risk of MRSA acquisition due to an MRSA-positive prior room occupant.

Lyme borreliosis, an infection caused by the tick-borne spirochete Borrelia burgdorferi, is a major health problem for populations in areas of endemicity in the Northern Hemisphere. In the present study we assessed the density of ticks and the prevalence of B. burgdorferi sensu lato among ticks in popular urban recreational areas of Helsinki, Finland. Altogether 1,688 Ixodes ricinus ticks were collected from five areas located within 5 km of the downtown section of Helsinki, and 726 of them (303 nymphs, 189 females, and 234 males) were randomly chosen for laboratory analysis. The midguts of the ticks were divided into three pieces, one for dark-field microscopy, one for cultivation in BSK-II medium, and one for PCR analysis. Ticks were found in all the study areas; their densities varied from 1 to 36 per 100 m along which a cloth was dragged. The rate of tick infection with B. burgdorferi sensu lato varied from 19 to 55%, with the average being 32%. Borellia afzelii was the most predominant genospecies in all the areas, and no B. burgdorferi sensu stricto isolates were detected. Only two ticks were concurrently infected with both B. afzelii and Borrelia garinii. Dark-field microscopy gave more positive results for B. burgdorferi than did cultivation or PCR analysis. However, the agreement between all three methods was fairly good. We conclude that Lyme borreliosis can be contracted even in urban environments not populated with large mammals like deer or elk. The disease should be taken into account in the differential diagnosis of certain symptoms of patients from these areas, and the use of measures to improve the awareness of the general population and health care officials of the risk of contracting the disease is warranted.

To assess the published evidence on the effectiveness of various approaches to the prevention of ankle sprains in athletes, we used textbooks, journals, and experts in the field of sports medicine to identify citations. We identified 113 studies reporting the risk of ankle sprains in sports, methods to provide support, the effect of these interventions on performance, and comparison of prevention efforts. The most common risk factor for ankle sprain in sports is history of a previous sprain. Ten citations of studies involving athletes in basketball, football, soccer, or volleyball compared alternative methods of prevention. Methods tested included wrapping the ankle with tape or cloth, orthoses, high-top shoes, or some combination of these methods. Most studies indicate that appropriately applied braces, tape, or orthoses do not adversely affect performance. Based on our review, we recommend that athletes with a sprained ankle complete supervised rehabilitation before returning to practice or competition, and those athletes suffering a moderate or severe sprain should wear an appropriate orthosis for at least 6 months. Both coaches and players must assume responsibility for prevention of injuries in sports. Methodologic limitations of published studies suggested several areas for future research.

Control of the Riverine (Palpalis) group of tsetse flies is normally achieved with stationary artificial devices such as traps or insecticide-treated targets. The efficiency of biconical traps (the standard control device), 1×1 m black targets and small 25×25 cm targets with flanking nets was compared using electrocuting sampling methods. The work was done on Glossina tachinoides and G. palpalis gambiensis (Burkina Faso), G. fuscipes quanzensis (Democratic Republic of Congo), G. f. martinii (Tanzania) and G. f. fuscipes (Kenya). The killing effectiveness (measured as the catch per m(2) of cloth) for small targets plus flanking nets is 5.5-15X greater than for 1 m(2) targets and 8.6-37.5X greater than for biconical traps. This has important implications for the costs of control of the Riverine group of tsetse vectors of sleeping sickness.

Flexible electronics is an emerging and promising technology for next generation of optoelectronic devices. Herein, hierarchical three-dimensional ZnCo(2)O(4) nanowire arrays/carbon cloth composites were synthesized as high performance binder-free anodes for Li-ion battery with the features of high reversible capacity of 1300-1400 mAh g(-1) and excellent cycling ability even after 160 cycles with a capacity of 1200 mAh g(-1). Highly flexible full batteries were also fabricated, exhibiting high flexibility, excellent electrical stability, and superior electrochemical performances.

In this Communication, we report the topotactic fabrication of self-supported nanoporous cobalt phosphide nanowire arrays on carbon cloth (CoP/CC) via low-temperature phosphidation of the corresponding Co(OH)F/CC precursor. The CoP/CC, as a robust integrated 3D hydrogen-evolving cathode, shows a low onset overpotential of 38 mV and a small Tafel slope of 51 mV dec(-1), and it maintains its catalytic activity for at least 80,00 s in acidic media. It needs overpotentials (η) of 67, 100, and 204 mV to attain current densities of 10, 20, and 100 mA cm(-2), respectively. Additionally, this electrode offers excellent catalytic performance and durability under neutral and basic conditions.

OBJECTIVE

A new class of rapid-deployment aortic valves has emerged with the potential to simplify minimally invasive aortic surgery and reduce crossclamp and cardiopulmonary bypass times. We report the 1-year clinical outcomes of aortic valve replacement with the EDWARDS INTUITY Valve System (Edwards Lifesciences LLC, Irvine, Calif) in the Surgical Treatment of Aortic Stenosis With a Next Generation Surgical Aortic Valve (TRITON) trial.

METHODS

Seventeen surgeons from 6 European centers treated 152 consecutive patients with aortic stenosis requiring valve replacement in a prospective, single-arm trial. A stented trileaflet bovine pericardial bioprosthesis with a balloon-expandable, cloth-covered stent frame at the inflow aspect was implanted in 146 patients (mean age, 75.5 ± 6.7 years; 52.7% were female). Five valve sizes were evaluated (19-27 mm); 58.9% of cases had isolated aortic valve replacement, and 41.1% of cases involved concomitant procedures. Minimally invasive surgical approaches occurred in 48.8% of the isolated aortic valve replacements. Patients were followed at discharge, 3 months, and 1 year postoperatively.

RESULTS

Implantation success was 96.1% (146/152), early valve-related mortality was 1.4% (2/146), and cumulative survival was 92.5% at a mean follow-up of 9.8 ± 5.1 months. Crossclamp time for isolated aortic valve replacement was 41.1 ± 10.6 minutes. Independent core laboratory-adjudicated mean effective orifice area and aortic valve pressure gradient were 1.7 ± 0.2 cm(2) and 8.8 ± 3.0 mm Hg at 3 months, and 1.7 ± 0.2 cm(2) and 8.4 ± 3.4 mm Hg at 1 year, respectively.

CONCLUSIONS

Implantation of the EDWARDS INTUITY Valve System is feasible, safe, and efficacious for aortic valve replacement. Aortic crossclamp and cardiopulmonary bypass times were reduced compared with those for conventional aortic valve replacement. Early hemodynamic performance was excellent and remained so up to 1 year.

BACKGROUND

Tsetse flies of the Palpalis group are the main vectors of sleeping sickness in Africa. Insecticide impregnated targets are one of the most effective tools for control. However, the cost of these devices still represents a constraint to their wider use. The objective was therefore to improve the cost effectiveness of currently used devices.

RESULTS

Experiments were performed on three tsetse species, namely Glossina palpalis gambiensis and G. tachinoides in Burkina Faso and G. p. palpalis in Côte d'Ivoire. The 1 × 1 m(2) black blue black target commonly used in W. Africa was used as the standard, and effects of changes in target size, shape, and the use of netting instead of black cloth were measured. Regarding overall target shape, we observed that horizontal targets (i.e. wider than they were high) killed 1.6-5x more G. p. gambiensis and G. tachinoides than vertical ones (i.e. higher than they were wide) (P < 0.001). For the three tsetse species including G. p. palpalis, catches were highly correlated with the size of the target. However, beyond the size of 0.75 m, there was no increase in catches. Replacing the black cloth of the target by netting was the most cost efficient for all three species.

CONCLUSIONS

Reducing the size of the current 1*1 m black-blue-black target to horizontal designs of around 50 cm and replacing black cloth by netting will improve cost effectiveness six-fold for both G. p. gambiensis and G. tachinoides. Studying the visual responses of tsetse to different designs of target has allowed us to design more cost-effective devices for the effective control of sleeping sickness and animal trypanosomiasis in Africa.

A technique for the isolation of gamma ray-sensitive Chinese hamster ovary (CHO) cell mutants is described, which uses nylon cloth replica plating and photography with dark-field illumination to directly monitor colonies for growth after gamma irradiation. Two gamma ray-sensitive mutants were isolated using this method. One of these cells (XR-1) had a two-slope survival curve: an initial steep slope and then a flattening of the curve at about 10% survival. Subsequently, it was found that this cell is sensitive to gamma irradiation in G1, early S, and late G2 phases of the cell cycle, whereas in the resistant phase (late S phase) its survival approaches that of the parental cells. The D37 in the sensitive G1 period is approximately 30 rads, compared with 300 rads of the parental cell. This mutant cell is also sensitive to killing by the DNA breaking agent, bleomycin, but is relatively insensitive to UV light and ethyl methane sulfonate, suggesting that the defect is specific for agents that produce DNA strand breakage.

Anthroponotic cutaneous leishmaniasis (ACL) is a significant public health problem in many towns and cities of south central Asia and the Middle East, resulting in disfigurement and disability which warrants preventive action. A randomized controlled trial was conducted in 1997/98 amongst a non-immune study population of 3666 people in Kabul, Afghanistan, to compare the efficacy of insecticide-treated nets (ITNs), insecticide-treated Islamic cloth wraps (chaddars) used to sleep in, and residual pyrethroid spraying of individual houses for the prevention of ACL. Dosages of insecticide were: ITNs with permethrin, 0.5 g/m2; chaddars with permethrin, 1 g/m2; rooms with lambdacyhalothrin, 30 mg/m2. Cases of ACL were diagnosed on clinical criteria. At the end of the trial period (15 months) the incidence of ACL amongst controls was 7.2%, amongst ITN users 2.4% (OR 0.31, 95% CI 0.2-0.5), amongst impregnated chaddar users 2.5% (OR 0.33, 95% CI 0.2-0.6) and amongst residents of sprayed houses 4.4% (OR 0.60, 95% CI 0.3-0.95). ITNs and impregnated chaddars were equally effective, providing about 65% protective efficacy, with approximately 40% protective efficacy attributable to individual house spraying. No significant differences for age or sex were found between new cases in the intervention and control groups. No serious side-effects were reported and interventions were generally popular; ITNs were the most popular, followed by residual spraying and then impregnated chaddars.

Hospital cleaning continues to attract patient, media and political attention. In the UK it is still primarily assessed via visual inspection, which can be misleading. Calls have therefore been made for a more objective approach to assessing surface cleanliness. To improve the management of hospital cleaning the use of adenosine triphosphate (ATP) in combination with microbiological analysis has been proposed, with a general ATP benchmark value of 500 relative light units (RLU) for one combination of test and equipment. In this study, the same test combination was used to assess cleaning effectiveness in a 1300-bed teaching hospital after routine and modified cleaning protocols. Based upon the ATP results a revised stricter pass/fail benchmark of 250 RLU is proposed for the range of surfaces used in this study. This was routinely achieved using modified best practice cleaning procedures which also gave reduced surface counts with, for example, aerobic colony counts reduced from >100 to <2.5 cfu/cm(2), and counts of Staphylococcus aureus reduced from up to 2.5 to <1 cfu/cm(2) (95% of the time). Benchmarking is linked to incremental quality improvements and both the original suggestion of 500 RLU and the revised figure of 250 RLU can be used by hospitals as part of this process. They can also be used in the assessment of novel cleaning methods, such as steam cleaning and microfibre cloths, which have potential use in the National Health Service.

Despite recent improvements in child survival in sub-Saharan Africa, neonatal mortality rates remain largely unchanged. This study aimed to determine the frequency of delivery and newborn-care practices in southern Tanzania, where neonatal mortality is higher than the national average. All households in five districts of Southern Tanzania were approached to participate. Of 213,220 female residents aged 13-49 years, 92% participated. Cross-sectional, retrospective data on childbirth and newborn care practices were collected from 22,243 female respondents who had delivered a live baby in the preceding year. Health facility deliveries accounted for 41% of births, with nearly all non-facility deliveries occurring at home (57% of deliveries). Skilled attendants assisted 40% of births. Over half of women reported drying the baby and over a third reported wrapping the baby within 5 minutes of delivery. The majority of mothers delivering at home reported that they had made preparations for delivery, including buying soap (84%) and preparing a cloth for drying the child (85%). Although 95% of these women reported that the cord was cut with a clean razor blade, only half reported that it was tied with a clean thread. Furthermore, out of all respondents 10% reported that their baby was dipped in cold water immediately after delivery, around two-thirds reported bathing their babies within 6 hours of delivery, and 28% reported putting something on the cord to help it dry. Skin-to-skin contact between mother and baby after delivery was rarely practiced. Although 83% of women breastfed within 24 hours of delivery, only 18% did so within an hour. Fewer than half of women exclusively breastfed in the three days after delivery. The findings suggest a need to promote and facilitate health facility deliveries, hygienic delivery practices for home births, delayed bathing and immediate and exclusive breastfeeding in Southern Tanzania to improve newborn health.

Insecticide-treated mosquito nets (ITN) provide excellent protection against malaria; however, they have a number of shortcomings that are particularly evident in politically unstable countries or countries at war: not everyone at risk can necessarily afford a net, nets may be difficult to obtain or import, nets may not be suitable for migrants or refugees sleeping under tents or plastic shelter. There is a need to develop cheaper, locally appropriate alternatives for the most impoverished and for victims of complex emergencies. Afghan women, in common with many Muslim peoples of Asia, wear a veil or wrap known as a chaddar to cover the head and upper body. This cloth doubles as a sheet at night, when they are used by both sexes. A randomized controlled trial was undertaken in which 10% of the families of an Afghan refugee camp (population 3950) in north-western Pakistan had their chaddars and top-sheets treated with permethrin insecticide at a dosage of 1 g/m2 while a further 10% had their chaddars treated with placebo formulation. Malaria episodes were recorded by passive case detection at the camp's health centre. From August to November the odds of having a falciparum or vivax malaria episode were reduced by 64% in children aged 0-10 years and by 38% in refugees aged < 20 years in the group using permethrin-treated chaddars and top-sheets. Incidence in refugees over 20 years of age was not significantly reduced. The cost of the permethrin treatment per person protected (US$0.17) was similar to that for treating bednets (and cost only 10-20% of the price of a new bednet). An entomological study simulating real-life conditions indicated that host-seeking mosquitoes were up to 70% less successful at feeding on men sleeping under treated chaddars and some were killed by the insecticide. Permethrin-treated top-sheets and blankets should provide appropriate and effective protection from malaria in complex emergencies. In Islamic and non-Islamic countries in Asia, treated chaddars and top-sheets should offer a satisfactory solution for the most vulnerable who cannot afford treated nets.

Three longitudinal studies are reported in which 6-8-month-old infants were tested on means-end problems involving pulling a cloth to retrieve a toy. Production of intentional means-end behavior increased between 6 and 7 months, but although 6-month-olds' behavior was unaffected by the presence or absence of a toy on the cloth, 7-month-olds more often produced means-end sequences when a toy could be retrieved. Infants' performance remained the same when the cloth was either attached to the toy or separate, suggesting that goal-subgoal conflict does not interfere with performance of means-end sequences. By 8 months, infants could appropriately adjust their means-end behavior to the distance of the toy. These results confirm J. Piaget's (1953) original description of a shift from transitional to intentional means-end behavior and suggest that development of means-end behavior involves acquisition of knowledge of appropriate means-end relations.

OBJECTIVE

To demonstrate whether daily bathing with cloths impregnated with 2% chlorhexidine gluconate will decrease colonization of resistant bacteria and reduce the rates of health care-associated infections in critically injured patients.

METHODS

Retrospective analysis of data collected 6 months before and after institution of a chlorhexidine bathing protocol.

METHODS

A 12-bed intensive care unit in a level I trauma center.

METHODS

Two hundred eighty-six severely injured patients underwent daily chlorhexidine bathing during the 6-month intervention; 253 patients were bathed without chlorhexidine prior to the intervention.

METHODS

Daily chlorhexidine bathing.

METHODS

Rates of ventilator-associated pneumonia (VAP), bloodstream infection, and colonization with resistant organisms (methicillin-resistant Staphylococcus aureus [MRSA] or Acinetobacter species).

RESULTS

Baseline patient and injury characteristics were similar between cohorts. Patients receiving chlorhexidine baths were significantly less likely to acquire a catheter-related bloodstream infection than comparators (2.1 vs 8.4 infections per 1000 catheter-days, P = .01). The incidence of VAP was not affected by chlorhexidine baths (16.9 vs 21.6 infections per 1000 ventilator-days in those with vs those without chlorhexidine baths, respectively, P = .30). However, patients who received chlorhexidine baths were less likely to develop MRSA VAP (1.6 vs 5.7 infections per 1000 ventilator-days, P = .03). The rate of colonization with MRSA (23.3 vs 69.3 per 1000 patient-days, P < .001) and Acinetobacter (1.0 vs 4.6 per 1000 patient-days, P = .36) was significantly lower in the chlorhexidine group than in the comparison group.

CONCLUSIONS

Daily bathing of trauma patients with cloths impregnated with 2% chlorhexidine gluconate is associated with a decreased rate of colonization by MRSA and Acinetobacter and lower rates of catheter-related bloodstream infection and MRSA VAP.

Cross-sectional studies have suggested that intravaginal practices, such as douching or "dry sex," may increase women's susceptibility to infection with human immunodeficiency virus (HIV). The authors examined the temporal nature of this association in a cohort of South African women. At enrollment (2001-2002), 4,089 women were tested for HIV infection. Participants reported their intravaginal practices at a 6-month follow-up visit and were followed with repeat HIV testing for up to 24 months. Among the 3,570 women who were HIV-negative at enrollment, 26% reported some type of intravaginal practice, mostly washing inside the vagina with water and/or cloth as part of daily hygiene. During follow-up, 85 incident HIV infections were observed. Intravaginal practices were associated with prevalent HIV at enrollment (adjusted odds ratio = 1.50, 95% confidence interval: 1.22, 1.85), but during follow-up there was no association between intravaginal practices and incident HIV (adjusted hazard ratio = 1.04, 95% confidence interval: 0.65, 1.68). These findings may be explained by a reversal of the causal sequence assumed for this association, since intravaginal practices may be undertaken in response to vaginal infections that occur more commonly among HIV-infected women. Intravaginal practices appear unlikely to be a cofactor in the male-to-female transmission of HIV in this setting.

Chinese hamster ovary (CHO) cell mutants that required exogenously added phosphatidylserine for cell growth were isolated by using the replica technique with polyester cloth, and three such mutants were characterized. Labeling experiments on intact cells with 32Pi and L-[U-14C]serine revealed that a phosphatidylserine auxotroph, designated as PSA-3, was strikingly defective in phosphatidylserine biosynthesis. When cells were grown for 2 days without phosphatidylserine, the phosphatidylserine content of PSA-3 was about one-third of that of the parent. In extracts of the mutant, the enzymatic activity of the base-exchange reaction of phospholipids with serine producing phosphatidylserine was reduced to 33% of that in the parent; in addition, the activities of base-exchange reactions of phospholipids with choline and ethanolamine in the mutant were also reduced to 1 and 45% of those in the parent, respectively. Furthermore, it was demonstrated that the serine-exchange activity in the parent was inhibited approximately 60% when choline was added to the reaction mixture whereas that in the mutant was not significantly affected. From the results presented here, we conclude the following. There are at least two kinds of serine-exchange enzymes in CHO cells; one (serine-exchange enzyme I) can catalyze the base-exchange reactions of phospholipids with serine, choline, and ethanolamine while the other (serine-exchange enzyme II) does not use the choline as a substrate. Serine-exchange enzyme I, in which mutant PSA-3 is defective, plays a major role in phosphatidylserine biosynthesis in CHO cells. Serine-exchange enzyme I is essential for the growth of CHO cells.

The relationship in sugarcane (Saccharum spp.) between photosynthetic source tissue and sink material was examined through manipulation of the sink:source ratio of field-grown Saccharum spp. hybrid cv. N19 (N19). To enhance sink strength, all leaves, except for the third fully expanded leaf, were enclosed in 90% shade cloth for varying periods of time. Variations in sucrose, glucose and fructose concentrations were measured and the effects of shading on the leaf gas exchange and fluorescence characteristics recorded. Changes in carbon partitioning caused by shading were examined based on the uptake and translocation of fixed 14CO2. Following a decline in sucrose concentrations in young internodal tissue and shaded leaves, significant increases in the CO2-saturated photosynthetic rate (Jmax), carboxylation efficiency (CE) and electron transport rate were observed in unshaded leaves after 8 d of shading treatment. It was concluded that up-regulation of source-leaf photosynthetic capacity is correlated with a decrease in assimilate availability to acropetal culm sink tissue. Furthermore, a significant relationship was revealed between source hexose concentration and photosynthetic activity.

SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), is thought to be transmitted mainly by person-to-person contact (1). Implementation of nationwide public health orders to limit person-to-person interaction and of guidance on personal protective practices can slow transmission (2,3). Such strategies can include stay-at-home orders, business closures, prohibitions against mass gatherings, use of cloth face coverings, and maintenance of a physical distance between persons (2,3). To assess and understand public attitudes, behaviors, and beliefs related to this guidance and COVID-19, representative panel surveys were conducted among adults aged ≥18 years in New York City (NYC) and Los Angeles, and broadly across the United States during May 5-12, 2020. Most respondents in the three cohorts supported stay-at-home orders and nonessential business closures* (United States, 79.5%; New York City, 86.7%; and Los Angeles, 81.5%), reported always or often wearing cloth face coverings in public areas (United States, 74.1%, New York City, 89.6%; and Los Angeles 89.8%), and believed that their state's restrictions were the right balance or not restrictive enough (United States, 84.3%; New York City, 89.7%; and Los Angeles, 79.7%). Periodic assessments of public attitudes, behaviors, and beliefs can guide evidence-based public health decision-making and related prevention messaging about mitigation strategies needed as the COVID-19 pandemic evolves.

Cases of Lyme disease that occurred in Westchester County, an affluent suburb north of New York City, in 1983 were investigated in 1983 and 1984 to determine the presence of Ixodes dammini (Acari: Ixodidae) in the vicinity of the patients' homes. Small mammal trapping, drag cloth, and carbon dioxide-baited tick traps were used to sample ticks. In all but one of 11 cases investigated, I. dammini was found on or near well-maintained lawns in the immediate vicinity of the residences. A mark-release-recapture experiment to determine tick abundance in one 700 m2 lawn resulted in an estimate of 6800 adult ticks (approximately 1 per m2). Dark-field microscopic examination of tick midgut tissues revealed that 33% of nymphs and 55% of adult ticks from this lawn contained spirochetes. These data suggest that many cases of Lyme disease in Westchester County, New York, may be acquired at home as a result of activities on the lawn.