Proactive, that is, unsolicited, prosociality is a key component of our hyper-cooperation, which in turn has enabled the emergence of various uniquely human traits, including complex cognition, ...morality and cumulative culture and technology. However, the evolutionary foundation of the human prosocial sentiment remains poorly understood, largely because primate data from numerous, often incommensurable testing paradigms do not provide an adequate basis for formal tests of the various functional hypotheses. We therefore present the results of standardized prosociality experiments in 24 groups of 15 primate species, including humans. Extensive allomaternal care is by far the best predictor of interspecific variation in proactive prosociality. Proactive prosocial motivations therefore systematically arise whenever selection favours the evolution of cooperative breeding. Because the human data fit this general primate pattern, the adoption of cooperative breeding by our hominin ancestors also provides the most parsimonious explanation for the origin of human hyper-cooperation.
Across Africa, chimpanzees prey on army ants, typically using stick tools. Population differences in predation patterns reflect environmental as well as sociocultural factors. However, as for ...ecological constraints, we lack information about how the ants' defensive response unfolds over the course of a predatory attempt and how this influences chimpanzee reward. We studied these aspects of insectivory in the habitat of Nigerian chimpanzees through field experiments with previously used tools. The speed with which ants run up a tool decreased continuously during experimental dips into nests. This suggests that soldiers with long legs run up the tools first, before fanning out to deter the intruder. Workers attacking later on were increasingly smaller, thus running less fast. Yet, because more and more insects join the defence, harvesting yield (g dry weight) steadily increased for the first 17 min, to then drop markedly. We hypothesize that the length of dipping sessions by wild chimpanzees is limited by either diminishing return or discomfort caused by being continually bitten. Actual harvesting success cannot be reconstructed from ant remains in chimpanzee faeces without knowing what proportion of consumed insects is detectable in excreta. Through human self‐experiments, we found that only 10% of ingested ants are found in a subsequent excretion. Based on counts of ant heads in chimpanzee faeces, this translates into 12.9 g dry weight ingested per dipping session, which is far more than elsewhere. Although prey availability and harvesting technique varies across sites, our data still suggest a much greater yield for Nigeria. One reason for this may be a particular aggressiveness of Dorylus rubellus. While this is the only army ant species preyed upon in Nigeria, it is not regularly eaten elsewhere. Standardized experiments and faecal analyses across study sites will be necessary to better understand how ecological constraints influence chimpanzee myrmecophagy.
Abstract
Across
A
frica, chimpanzees prey on army ants, typically using stick tools. Population differences in predation patterns reflect environmental as well as sociocultural factors. However, as ...for ecological constraints, we lack information about how the ants' defensive response unfolds over the course of a predatory attempt and how this influences chimpanzee reward. We studied these aspects of insectivory in the habitat of
N
igerian chimpanzees through field experiments with previously used tools. The speed with which ants run up a tool decreased continuously during experimental dips into nests. This suggests that soldiers with long legs run up the tools first, before fanning out to deter the intruder. Workers attacking later on were increasingly smaller, thus running less fast. Yet, because more and more insects join the defence, harvesting yield (g dry weight) steadily increased for the first 17 min, to then drop markedly. We hypothesize that the length of dipping sessions by wild chimpanzees is limited by either diminishing return or discomfort caused by being continually bitten. Actual harvesting success cannot be reconstructed from ant remains in chimpanzee faeces without knowing what proportion of consumed insects is detectable in excreta. Through human self‐experiments, we found that only 10% of ingested ants are found in a subsequent excretion. Based on counts of ant heads in chimpanzee faeces, this translates into 12.9 g dry weight ingested per dipping session, which is far more than elsewhere. Although prey availability and harvesting technique varies across sites, our data still suggest a much greater yield for
N
igeria. One reason for this may be a particular aggressiveness of
D
orylus rubellus
. While this is the only army ant species preyed upon in
N
igeria, it is not regularly eaten elsewhere. Standardized experiments and faecal analyses across study sites will be necessary to better understand how ecological constraints influence chimpanzee myrmecophagy.
Therapies that improve survival in critically ill patients with coronavirus disease 2019 (COVID-19) are needed. Tocilizumab, a monoclonal antibody against the interleukin 6 receptor, may counteract ...the inflammatory cytokine release syndrome in patients with severe COVID-19 illness.
To test whether tocilizumab decreases mortality in this population.
The data for this study were derived from a multicenter cohort study of 4485 adults with COVID-19 admitted to participating intensive care units (ICUs) at 68 hospitals across the US from March 4 to May 10, 2020. Critically ill adults with COVID-19 were categorized according to whether they received or did not receive tocilizumab in the first 2 days of admission to the ICU. Data were collected retrospectively until June 12, 2020. A Cox regression model with inverse probability weighting was used to adjust for confounding.
Treatment with tocilizumab in the first 2 days of ICU admission.
Time to death, compared via hazard ratios (HRs), and 30-day mortality, compared via risk differences.
Among the 3924 patients included in the analysis (2464 male 62.8%; median age, 62 interquartile range {IQR}, 52-71 years), 433 (11.0%) received tocilizumab in the first 2 days of ICU admission. Patients treated with tocilizumab were younger (median age, 58 IQR, 48-65 vs 63 IQR, 52-72 years) and had a higher prevalence of hypoxemia on ICU admission (205 of 433 47.3% vs 1322 of 3491 37.9% with mechanical ventilation and a ratio of partial pressure of arterial oxygen to fraction of inspired oxygen of <200 mm Hg) than patients not treated with tocilizumab. After applying inverse probability weighting, baseline and severity-of-illness characteristics were well balanced between groups. A total of 1544 patients (39.3%) died, including 125 (28.9%) treated with tocilizumab and 1419 (40.6%) not treated with tocilizumab. In the primary analysis, during a median follow-up of 27 (IQR, 14-37) days, patients treated with tocilizumab had a lower risk of death compared with those not treated with tocilizumab (HR, 0.71; 95% CI, 0.56-0.92). The estimated 30-day mortality was 27.5% (95% CI, 21.2%-33.8%) in the tocilizumab-treated patients and 37.1% (95% CI, 35.5%-38.7%) in the non-tocilizumab-treated patients (risk difference, 9.6%; 95% CI, 3.1%-16.0%).
Among critically ill patients with COVID-19 in this cohort study, the risk of in-hospital mortality in this study was lower in patients treated with tocilizumab in the first 2 days of ICU admission compared with patients whose treatment did not include early use of tocilizumab. However, the findings may be susceptible to unmeasured confounding, and further research from randomized clinical trials is needed.
Concerns exist about deleterious renal effects of low-carbohydrate high-protein weight loss diets. This issue was addressed in a secondary analysis of a parallel randomized, controlled long-term ...trial.
Between 2003 and 2007, 307 obese adults without serious medical illnesses at three United States academic centers were randomly assigned to a low-carbohydrate high-protein or a low-fat weight-loss diet for 24 months. Main outcomes included renal filtration (GFR) indices (serum creatinine, cystatin C, creatinine clearance); 24-hour urinary volume; albumin; calcium excretion; and serum solutes at 3, 12, and 24 months.
Compared with the low-fat diet, low-carbohydrate high-protein consumption was associated with minor reductions in serum creatinine (relative difference, -4.2%) and cystatin C (-8.4%) at 3 months and relative increases in creatinine clearance at 3 (15.8 ml/min) and 12 (20.8 ml/min) months; serum urea at 3 (14.4%), 12 (9.0%), and 24 (8.2%) months; and 24-hour urinary volume at 12 (438 ml) and 24 (268 ml) months. Urinary calcium excretion increased at 3 (36.1%) and 12 (35.7%) months without changes in bone density or clinical presentations of new kidney stones.
In healthy obese individuals, a low-carbohydrate high-protein weight-loss diet over 2 years was not associated with noticeably harmful effects on GFR, albuminuria, or fluid and electrolyte balance compared with a low-fat diet. Further follow-up is needed to determine even longer-term effects on kidney function.
Severe Achalasia Causing Cor Pulmonale Bayoumi, Mahmoud; Kahn, Allon; Snyder, Diana L ...
The American journal of gastroenterology,
08/2020, Letnik:
115, Številka:
8
Journal Article
The aim of this study was to determine the short- and long-term effect of rotifer DHA and taurine, individually and through interaction, on larval tissue levels of these nutrients, prey hunting ...success, growth performance and retinal opsin gene expression, at the end of rotifer and Artemia feeding in developing gilthead sea bream (GSB) (Sparus aurata) larvae. The experiment was designed as a 3 × 3 factorial study in triplicate tanks per treatment. Three levels of rotifer taurine (1.2, 4.9, 10.8 mg g−1 DW) and DHA (5.2, 6.8, 10.1 mg g−1 DW) were tested on 2–14 dph larvae in twenty-seven 400 L V-tanks. All fish were then fed non-taurine enriched Artemia nauplii until 30 dph. There was a significant (P = 0.014) rotifer DHA effect on prey consumption in 13 dph larvae, while rotifer taurine had no marked influence. Rotifer DHA significantly (P = 0.0001) promoted growth (dry weight) alone (P = 0.0001) and through interaction with taurine (P = 0.009) in 31 dph larvae. Moreover, the results implied that rotifer taurine increased assimilation into fish tissue, which resulted in enhanced growth only when prey DHA was below the minimum GSB requirement. Rotifer DHA significantly (P < 0.0001) up-regulated short-wave sensitivity opsin gene expression in 14 dph larvae, while taurine alone had no significant effect. On the other hand, rotifer DHA and taurine individually and through interaction markedly (P < 0.0001, P = 0.022, P < 0.0001, respectively) up-regulated long-wave sensitivity opsin gene expression. However, both prey DHA and taurine did not clearly affect the expression of cone rhodopsin-like 2a and 2b opsin genes. Having said that, rotifer DHA and taurine individually and through interaction significantly (P = 0.034, P = 0.015, P = 0.0005, respectively) affected the gene expression of rod rhodopsin 1. In 31 dph larvae, there was a marked (P < 0.05) rotifer DHA and taurine effect individually and through interaction on the expression of most of the opsin genes analyzed. DHA modulation of the expression of the four cone and rod opsin genes was higher than taurine in younger larvae while taurine appears more dominant over DHA regulating the gene expression of opsin genes in older fish.
•Rotifer taurine content increases DHA levels in GSB larvae, which can improve growth.•GSB gene expression of cone opsins increased from 1 to 14 dph and then decreased to 31 dph.•Gene expression of rod rhodopsin steadily increased from 1 to 31 dph in GSB larvae.•Rotifer taurine and DHA singly and through interaction modulates larval gene expression of cone and rod opsins.
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