Title: High Heat, Humidity Could Affect More Than 1.2 Billion People by End of Century
Category: Health News
Created: 3/24/2020 12:00:00 AM
Last Editorial Review: 3/25/2020 12:00:00 AM

Title: Women Are Much Safer Drivers Than Men, British Study Finds
Category: Health News
Created: 4/7/2020 12:00:00 AM
Last Editorial Review: 4/7/2020 12:00:00 AM

ABSTRACT

Bacteria harbor viruses called bacteriophages that, like all viruses, co-opt the host cellular machinery to replicate. Although this relationship is at first glance parasitic, there are social interactions among and between bacteriophages and their bacterial hosts. These social interactions can take on many forms, including cooperation, altruism, and cheating. Such behaviors among individuals in groups of bacteria have been well described. However, the social nature of some interactions between phages or phages and bacteria is only now becoming clear. We are just beginning to understand how bacteriophages affect the sociobiology of bacteria, and we know even less about social interactions within bacteriophage populations. In this review, we discuss recent developments in our understanding of bacteriophage sociobiology, including how selective pressures influence the outcomes of social interactions between populations of bacteria and bacteriophages. We also explore how tripartite social interactions between bacteria, bacteriophages, and an animal host affect host-microbe interactions. Finally, we argue that understanding the sociobiology of bacteriophages will have implications for the therapeutic use of bacteriophages to treat bacterial infections.

ABSTRACT

Cold seeps and hydrothermal vents deliver large amounts of methane and other gaseous alkanes into marine surface sediments. Consortia of archaea and partner bacteria thrive on the oxidation of these alkanes and its coupling to sulfate reduction. The inherently slow growth of the involved organisms and the lack of pure cultures have impeded the understanding of the molecular mechanisms of archaeal alkane degradation. Here, using hydrothermal sediments of the Guaymas Basin (Gulf of California) and ethane as the substrate, we cultured microbial consortia of a novel anaerobic ethane oxidizer, "Candidatus Ethanoperedens thermophilum" (GoM-Arc1 clade), and its partner bacterium "Candidatus Desulfofervidus auxilii," previously known from methane-oxidizing consortia. The sulfate reduction activity of the culture doubled within one week, indicating a much faster growth than in any other alkane-oxidizing archaea described before. The dominance of a single archaeal phylotype in this culture allowed retrieval of a closed genome of "Ca. Ethanoperedens," a sister genus of the recently reported ethane oxidizer "Candidatus Argoarchaeum." The metagenome-assembled genome of "Ca. Ethanoperedens" encoded a complete methanogenesis pathway including a methyl-coenzyme M reductase (MCR) that is highly divergent from those of methanogens and methanotrophs. Combined substrate and metabolite analysis showed ethane as the sole growth substrate and production of ethyl-coenzyme M as the activation product. Stable isotope probing demonstrated that the enzymatic mechanism of ethane oxidation in "Ca. Ethanoperedens" is fully reversible; thus, its enzymatic machinery has potential for the biotechnological development of microbial ethane production from carbon dioxide.

IMPORTANCE In the seabed, gaseous alkanes are oxidized by syntrophic microbial consortia that thereby reduce fluxes of these compounds into the water column. Because of the immense quantities of seabed alkane fluxes, these consortia are key catalysts of the global carbon cycle. Due to their obligate syntrophic lifestyle, the physiology of alkane-degrading archaea remains poorly understood. We have now cultivated a thermophilic, relatively fast-growing ethane oxidizer in partnership with a sulfate-reducing bacterium known to aid in methane oxidation and have retrieved the first complete genome of a short-chain alkane-degrading archaeon. This will greatly enhance the understanding of nonmethane alkane activation by noncanonical methyl-coenzyme M reductase enzymes and provide insights into additional metabolic steps and the mechanisms underlying syntrophic partnerships. Ultimately, this knowledge could lead to the biotechnological development of alkanogenic microorganisms to support the carbon neutrality of industrial processes.

ABSTRACT

Ever since the discovery of the first rare earth element (REE)-dependent enzyme, the physiological role of lanthanides has become an emerging field of research due to the environmental implications and biotechnological opportunities. In Pseudomonas putida KT2440, the two pyrroloquinoline quinone-dependent alcohol dehydrogenases (PQQ-ADHs) PedE and PedH are inversely regulated in response to REE availability. This transcriptional switch is orchestrated by a complex regulatory network that includes the PedR2/PedS2 two-component system and is important for efficient growth on several alcoholic volatiles. To study whether cellular responses beyond the REE switch exist, the differential proteomic responses that occur during growth on various model carbon sources were analyzed. Apart from the Ca²⁺-dependent enzyme PedE, the differential abundances of most identified proteins were conditional. During growth on glycerol—and concomitant with the proteomic changes—lanthanum (La³⁺) availability affected different growth parameters, including the onset of logarithmic growth and final optical densities. Studies with mutant strains revealed a novel metabolic route for glycerol utilization, initiated by PedE and/or PedH activity. Upon oxidation to glycerate via glyceraldehyde, phosphorylation by the glycerate kinase GarK most likely yields glycerate-2-phosphate, which is eventually channeled into the central metabolism of the cell. This new route functions in parallel with the main degradation pathway encoded by the glpFKRD operon and provides a growth advantage to the cells by allowing an earlier onset of growth with glycerol as the sole source of carbon and energy.

IMPORTANCE The biological role of REEs has long been underestimated, and research has mainly focused on methanotrophic and methylotrophic bacteria. We have recently demonstrated that P. putida, a plant growth-promoting bacterium that thrives in the rhizosphere of various food crops, possesses a REE-dependent alcohol dehydrogenase (PedH), but knowledge about REE-specific effects on physiological traits in nonmethylotrophic bacteria is still scarce. This study demonstrates that the cellular response of P. putida to lanthanum (La³⁺) is mostly substrate specific and that La³⁺ availability highly affects the growth of cells on glycerol. Further, a novel route for glycerol metabolism is identified, which is initiated by PedE and/or PedH activity and provides a growth advantage to this biotechnologically relevant organism by allowing a faster onset of growth. Overall, these findings demonstrate that lanthanides can affect physiological traits in nonmethylotrophic bacteria and might influence their competitiveness in various environmental niches.

Addressing social drivers of health in medical education—through community engagement experiences—is essential for health equity and the development of future physicians. While this was written before the COVID-19 pandemic, these practices will gain even more importance as we come together to better understand its health and community implications in North Carolina and the United States.

Phosphatidylcholine and phosphatidylethanolamine are two major phospholipid classes in eukaryotes. Each biosynthesis pathway starts with the phosphorylation of choline (Cho) or ethanolamine (Etn) catalyzed by either choline or ethanolamine kinase (CEK). Arabidopsis contains four CEK isoforms, but their isozyme-specific roles in metabolism and development are poorly described. Here, we showed that these four CEKs have distinct substrate specificities in vitro. While CEK1 and CEK2 showed substrate preference for Cho over Etn, CEK3 and CEK4 had clear substrate specificity for Cho and Etn, respectively. In vivo, CEK1, CEK2, and CEK3 exhibited kinase activity for Cho but not Etn, although the latter two isoforms showed rather minor contributions to total Cho kinase activity in both shoots and roots. The knockout mutants of CEK2 and CEK3 both affected root growth, and these isoforms had nonoverlapping cell-type-specific expression patterns in the root meristematic zone. In-depth phenotype analysis, as well as chemical and genetic complementation, revealed that CEK3, a Cho-specific kinase, is involved in cell elongation during root development. Phylogenetic analysis of CEK orthologs in Brassicaceae species showed evolutionary divergence between Etn kinases and Cho kinases. Collectively, our results demonstrate the distinct roles of the four CEK isoforms in Cho/Etn metabolism and plant development.

David J. Pritchard and Mario Vallejo-Marin

Vibrations play an important role in insect behaviour. In bees, vibrations are used in a variety of contexts including communication, as a warning signal to deter predators and during pollen foraging. However, little is known about how the biomechanical properties of bee vibrations vary across multiple behaviours within a species. In this study, we compared the properties of vibrations produced by Bombus terrestris audax (Hymenoptera: Apidae) workers in three contexts: during flight, during defensive buzzing, and in floral vibrations produced during pollen foraging on two buzz-pollinated plants (Solanum, Solanaceae). Using laser vibrometry, we were able to obtain contactless measures of both the frequency and amplitude of the thoracic vibrations of bees across the three behaviours. Despite all three types of vibrations being produced by the same power flight muscles, we found clear differences in the mechanical properties of the vibrations produced in different contexts. Both floral and defensive buzzes had higher frequency and amplitude velocity, acceleration, and displacement than the vibrations produced during flight. Floral vibrations had the highest frequency, amplitude velocity and acceleration of all the behaviours studied. Vibration amplitude, and in particular acceleration, of floral vibrations has been suggested as the key property for removing pollen from buzz-pollinated anthers. By increasing frequency and amplitude velocity and acceleration of their vibrations during vibratory pollen collection, foraging bees may be able to maximise pollen removal from flowers, although their foraging decisions are likely to be influenced by the presumably high cost of producing floral vibrations.

Scarlet J. Park and William W. Ja

Factors that mediate ethanol preference in Drosophila melanogaster are not well understood. A major confound has been the use of diverse methods to estimate ethanol consumption. We measured fly consumptive ethanol preference on base diets varying in nutrients, taste, and ethanol concentration. Both sexes showed ethanol preference that was abolished on high nutrient concentration diets. Additionally, manipulating total food intake without altering the nutritive value of the base diet or the ethanol concentration was sufficient to evoke or eliminate ethanol preference. Absolute ethanol intake and food volume consumed were stronger predictors of ethanol preference than caloric intake or the dietary caloric content. Our findings suggest that the effect of the base diet on ethanol preference is largely mediated by total consumption associated with the delivery medium, which ultimately determines the level of ethanol intake. We speculate that a physiologically relevant threshold for ethanol intake is essential for preferential ethanol consumption.

Premature infants have a higher incidence of indirect hyperbilirubinemia than term infants. Management of neonatal indirect hyperbilirubinemia in late preterm and term neonates has been well addressed by recognized, consensus-based guidelines. However, the extension of these guidelines to the preterm population has been an area of uncertainty because of limited evidence. This leads to variation in clinical practice and lack of recognition of the spectrum of bilirubin-induced neurologic dysfunction (BIND) in this population. Preterm infants are metabolically immature and at higher risk for BIND at lower bilirubin levels than their term counterparts. Early use of phototherapy to eliminate BIND and minimize the need for exchange transfusion is the goal of treatment in premature neonates. Although considered relatively safe, phototherapy does have side effects, and some NICUs tend to overuse phototherapy. In this review, we describe the epidemiology and pathophysiology of BIND in preterm neonates, and discuss our approach to standardized management of indirect hyperbilirubinemia in the vulnerable preterm population. The proposed treatment charts suggest early use of phototherapy in preterm neonates with the aim of reducing exposure to high irradiance levels, minimizing the need for exchange transfusions, and preventing BIND. The charts are pragmatic and have additional curves for stopping phototherapy and escalating its intensity. Having a standardized approach would support future research and quality improvement initiatives that examine dose and duration of phototherapy exposure with relation to outcomes.

Tobacco use is a persistent public health issue. It kills up to half its users and is the cause of nearly 90% of all lung cancers. The main psychoactive component of tobacco is nicotine, primarily responsible for its abuse-related effects. Accordingly, most pharmacotherapies for smoking cessation target nicotinic acetylcholine receptors (nAChRs), nicotine’s major site of action in the brain. The goal of the current review is twofold: first, to provide a brief overview of the most commonly used behavioral procedures for evaluating smoking cessation pharmacotherapies and an introduction to pharmacokinetic and pharmacodynamic properties of nicotine important for consideration in the development of new pharmacotherapies; and second, to discuss current and potential future pharmacological interventions aimed at decreasing tobacco use. Attention will focus on the potential for allosteric modulators of nAChRs to offer an improvement over currently approved pharmacotherapies. Additionally, given increasing public concern for the potential health consequences of using electronic nicotine delivery systems, which allow users to inhale aerosolized solutions as an alternative to smoking tobacco, an effort will be made throughout this review to address the implications of this relatively new form of nicotine delivery, specifically as it relates to smoking cessation.

In iron-depleted women without anemia, oral iron supplements induce an increase in serum hepcidin (SHep) that persists for 24 hours, decreasing iron absorption from supplements given later on the same or next day. Consequently, iron absorption from supplements is highest if iron is given on alternate days. Whether this dosing schedule is also beneficial in women with iron-deficiency anemia (IDA) given high-dose iron supplements is uncertain. The primary objective of this study was to assess whether, in women with IDA, alternate-day administration of 100 and 200 mg iron increases iron absorption compared to consecutive-day iron administration. Secondary objectives were to correlate iron absorption with SHep and iron status parameters. We performed a cross-over iron absorption study in women with IDA (n=19; median hemoglobin 11.5 mg/dL; mean serum ferritin 10 mg/L) who received either 100 or 200 mg iron as ferrous sulfate given at 8 AM on days 2, 3 and 5 labeled with stable iron isotopes 57Fe, 58Fe and 54Fe; after a 16-day incorporation period, the other labeled dose was given at 8 AM on days 23, 24 and 26 (days 2, 3 and 5 of the second period). Iron absorption on days 2 and 3 (consecutive) and day 5 (alternate) was assessed by measuring erythrocyte isotope incorporation. For both doses, SHep was higher on day 3 than on day 2 (P<0.001) or day 5 (P<0.01) with no significant difference between days 2 and 5. Similarly, for both doses, fractional iron absorption (FIA) on days 2 and 5 was 40-50% higher than on day 3 (P<0.001), while absorption on day 2 did not differ significantly from day 5. There was no significant difference in the incidence of gastrointestinal side effects comparing the two iron doses (P=0.105). Alternate day dosing of oral iron supplements in anemic women may be preferable because it sharply increases FIA. If needed, to provide the same total amount of iron with alternate day dosing, twice the daily target dose should be given on alternate days, as total iron absorption from a single dose of 200 mg given on alternate days was approximately twice that from 100 mg given on consecutive days (P<0.001). In IDA, even if hepatic hepcidin expression is strongly suppressed by iron deficiency and erythropoietic drive, the intake of oral iron supplements leads to an acute hepcidin increase for 24 hours. The study was funded by ETH Zürich, Switzerland. This study has been registered at www.clinicaltrials.gov as #NCT03623997.

Với 15 năm kinh nghiệm cải tạo không gian sống, chuyên gia thiết kế nội thất Jess Cooney và đội ngũ của mình đã biến một nhà vòm trắc địa thành ngôi nhà thanh lịch, thân thiện với gia đình.

Trong những ngôi nhà ở hay tòa nhà văn phòng, vách ngăn cầu thang bằng kính luôn là chi tiết kiến trúc thu hút mọi ánh nhìn dù hiện diện ở bất cứ vị trí nào. Nhưng bạn có nhận thấy rằng, chúng sẽ càng đặc biệt thú vị hơn khi kết hợp cùng một số vật liệu thô mộc, chẳng hạn như gỗ hay bê tông?

Làm vườn thẳng đứng hay làm vườn tường hiểu đơn giản là trồng cây theo chiều thẳng đứng, khác hẳn với kiểu trồng cây truyền thống. Chính nhờ cấu trúc thẳng đứng nên khu vườn có thể được bố trí dọc theo ngôi nhà, hành lang, bức tường... mà không chiếm dụng quá nhiều diện tích, rất phù hợp với những không gian khiêm tốn như nhà phố.

Diện tích nhà nhỏ nhưng vẫn cần có không gian để trưng bày tranh, ảnh và đồ trang trí. Bằng cách thiết kế cầu thang gỗ đa năng, vừa giữ vai trò giao thông, vừa để lưu trữ và trưng bày, kiến trúc sư đã khiến gia chủ hài lòng 100%.

Nhà xây từ năm 1983, sau nhiều lần nâng cấp, sửa chữa đường, hiện tại nền nhà đã thấp hơn đường, thường xuyên bị ngập nước sau mỗi trận mưa. Chưa kể, kiến trúc nhà đã lạc hậu, buộc chủ nhà phải cải tạo lại theo phong cách hiện đại.

Những gợi ý phối màu đơn giản nhưng không bao giờ lỗi mốt dưới đây sẽ giúp bạn không bị bí ý tưởng khi thiết kế không gian nội thất.