976 research outputs found
Nutritional Quality of Leaves and Unripe Fruit Consumed as Famine Foods by the Flying Foxes of Samoa
Many tropical herbivores alter their diets throughout the year in
response to different levels of food availability. Fruit bats, including Pteropus
samoensis Peale and Pteropus tonganus Quoy & Gaimard, are phytophagous
species that may increase their consumption of foods such as unripe fruit and
leaves in periods of low fruit diversity and volume. These periods include the
tropical dry season or following the frequent hurricanes that batter the Samoan
Archipelago. We examined the nutritional composition of leaves and immature
fruits and compared the levels of organic and mineral nutrients with those of
ripe fruit. We used principal components analysis (PCA) to examine patterns
of variation in nutrient components of leaves, unripe fruit, and ripe fruit, as
well as to compare the mean levels of nutrients. Overall, unripe fruit provided
levels of nutrients comparable with those of ripe fruit of the same species for
many organic and mineral components. Unripe fruit were only half as rich in
iron as ripe fruit, but unripe fruit had high levels of calcium compared with
ripe fruit of the same species. Leaves are often cited as a rich source of protein
for fruit bats, and our results were consistent with this suggestion. Leaves were
also found to be rich in zinc, manganese, and calcium. Therefore, flying foxes
and other herbivores probably do not avoid unripe fruits and leaves because of
their low nutrient levels. It may be that these famine foods are not normally
consumed because of the presence of secondary compounds, low concentrations
of palatable sugars, or a distasteful and hard pericarp on unripe fruits
Recommended from our members
An isolated white-tailed deer (Odocoileus virginianus) population on St. John, US Virgin Islands shows low inbreeding and comparable heterozygosity to other larger populations
This is the first study to document the genetic diversity of the white-tailed deer population on St. John, US Virgin Islands. The island population was founded by a small number of animals, has very limited hunting or predation, and recently experienced a reduction in size following an extended drought in 2015. DNA samples were collected from hair from 23 anesthetized adult deer (13 males, 10 females) ranging in age from 1 to 8 years (3.36 ± 1.9 years) and also from fecal DNA samples, for a total of 42 individuals analyzed for genetic diversity. The St. John deer data set averaged 4.19 alleles per marker and demonstrates the second lowest number of alleles (A) when compared to other populations of Odocoileus virginianus (4.19). Heterozygosity was similar to the other studies (0.54) with little evidence of inbreeding. To explain the level of heterozygosity and level of inbreeding within the St. John population, three hypotheses are proposed, including the effect of intrinsic biological traits within the population, a recent infusion of highly heterogeneous loci from North American populations, and a consistent level of immigration from a nearby island. Additional work is needed to further understand the genetic history of the St. John and regional deer populations.
</p
Patterns of Amygdala Region Pathology in LATE-NC: Subtypes that Differ with Regard to TDP-43 Histopathology, Genetic Risk Factors, and Comorbid Pathologies
Transactive response (TAR) DNA-binding protein 43 kDa (TDP-43) pathology is a hallmark of limbic-predominant agerelated TDP-43 encephalopathy (LATE). The amygdala is afected early in the evolution of LATE neuropathologic change (LATE-NC), and heterogeneity of LATE-NC in amygdala has previously been observed. However, much remains to be learned about how LATE-NC originates and progresses in the brain. To address this, we assessed TDP-43 and other pathologies in the amygdala region of 184 autopsied subjects (median age=85 years), blinded to clinical diagnoses, other neuropathologic diagnoses, and risk genotype information. As previously described, LATE-NC was associated with older age at death, cognitive impairment, and the TMEM106B risk allele. Pathologically, LATE-NC was associated with comorbid hippocampal sclerosis (HS), myelin loss, and vascular disease in white matter (WM). Unbiased hierarchical clustering of TDP-43 inclusion morphologies revealed discernable subtypes of LATE-NC with distinct clinical, genetic, and pathologic associations. The most common patterns were: Pattern 1, with lamina II TDP-43+processes and preinclusion pathology in cortices of the amygdala region, and frequent LATE-NC Stage 3 with HS; Pattern 2, previously described as type-β, with neurofbrillary tangle-like TDP-43 neuronal cytoplasmic inclusions (NCIs), high Alzheimer’s disease neuropathologic change (ADNC), frequent APOE ε4, and usually LATE-NC Stage 2; Pattern 3, with round NCIs and thick neurites in amygdala, younger age at death, and often comorbid Lewy body disease; and Pattern 4 (the most common pattern), with tortuous TDP43 processes in subpial and WM regions, low ADNC, rare HS, and lower dementia probability. TDP-43 pathology with features of patterns 1 and 2 were often comorbid in the same brains. Early and mild TDP-43 pathology was often best described to be localized in the “amygdala region” rather than the amygdala proper. There were also important shared attributes across patterns. For example, all four patterns were associated with the TMEM106B risk allele. Each pattern also demonstrated the potential to progress to higher LATE-NC stages with confuent anatomical and pathological patterns, and to contribute to dementia. Although LATE-NC showed distinct patterns of initiation in amygdala region, there was also apparent shared genetic risk and convergent pathways of clinico-pathological evolution
The Diverse Solar Phase Curves of Distant Icy Bodies. II. The Cause of the Opposition Surges and Their Correlations
We collect well-measured opposition surge properties for many icy bodies
orbiting the Sun (mostly from our own observations) plus for many icy moons,
resulting in a data base of surface and orbital properties for 52 icy bodies.
(1) We put forward four criteria for determining whether the surge is being
dominated by shadow hiding (SH) or coherent backscattering (CB) based on
readily measured quantities. The CB surge mechanism dominates if the surge is
color dependent, the phase curve is steeper than 0.04 mag/deg, the phase curve
shape matches the CB model of Hapke, or if the albedo is higher than roughly
40%. (2) We find that virtually all of our sample have their phase curves
dominated by CB at low phase angles. (3) We present a graphical method to
determine the Hapke surge parameters B_C0 and h_C. (4) The Kuiper Belt Objects
(KBOs) and Centaurs have relatively high surge amplitudes, B_C0 > ~0.5 and
widths with h_C ~ 3 deg. (5) We find highly significant but loose correlations
between surge properties and the colors, albedos, and inclinations. We
interpret this as young surfaces tending to have low surge slopes, high albedo,
and gray colors. (6) Nereid has its surface properties similar to other icy
moons and greatly different from KBOs and Centaurs, so we conclude that Nereid
is likely a nearly-ejected inner Neptunian moon rather than a captured KBO.Comment: Astronomical Journal, in press, 41 pages, 5 figure
Test-retest reliability and effects of repeated testing and satiety on performance of an Emotional Test Battery
The P1vital® Oxford Emotional Test Battery (ETB) comprises five computerized tasks designed to assess cognition and emotional processing in human participants. It has been used in between-subjects experimental designs; however, it is unclear whether the battery can be used in crossover designs. This is of particular importance given the increasing use of ETB tasks for repeated assessment of depressed patients in clinical trials and clinical practice. In addition, although satiety state has been reported to affect performance on some cognitive and emotional tasks, it is not known whether it can influence performance on the ETB. Two studies explored these issues. In Experiment 1, 30 healthy women were tested on the ETB on 4 separate occasions (each a week apart) in a within-subjects design. In Experiment 2, another 30 healthy women were randomized to either a satiated or a hungry condition, where they were given an ad libitum lunch of cheese sandwiches, before (satiated) or after (hungry) they were asked to complete the ETB. Experiment 1 demonstrated good test-retest reliability for the ETB. One of the tasks was free from practice effects, whilst performance on the other four tasks stabilized after the first two sessions. In Experiment 2, eating to satiety only affected performance on a single ETB task. These results suggest that the ETB can be used in crossover designs after two initial training sessions. Further, as a robust satiety manipulation had only a limited effect on a single ETB task, it is unlikely that appetitive state will confound ETB performance
Changes to Health Parameters of White-Tailed Deer during a Drought in the US Virgin Islands
Resident white-tailed deer (Odocoileus virginianus) on St. John, US Virgin Islands offer a unique case study for understanding a population under pressure from climate change. During a 2015–2016 regional drought, deer health parameters including body condition, coat condition, tick prevalence, musculature, and stress hormones were tracked over three field seasons representing the onset, peak, and recovery phases of the drought. All health indicators showed significant change over the course of the drought, and post-hoc tests suggest some indicators (body condition, musculature, and ticks) were more sensitive during drought onset. High levels of cortisol during the peak period indicated substantial stress to the population, which normalized during recovery. The strongest correlations were between overall health/body condition and musculature and overall health/body condition and coat condition. The weakest correlations were between ticks and the remaining three variables. These results support the hypothesis that various measures of deer health are related. The frequency and intensity of droughts and environmental stressors are predicted to increase in the future due to climate change, which will further challenge this island deer population
Integrated next-generation sequencing of 16S rDNA and metaproteomics differentiate the healthy urine microbiome from asymptomatic bacteriuria in neuropathic bladder associated with spinal cord injury
Background
Clinical dogma is that healthy urine is sterile and the presence of bacteria with an inflammatory response is indicative of urinary tract infection (UTI). Asymptomatic bacteriuria (ABU) represents the state in which bacteria are present but the inflammatory response is negligible. Differentiating ABU from UTI is diagnostically challenging, but critical because overtreatment of ABU can perpetuate antimicrobial resistance while undertreatment of UTI can result in increased morbidity and mortality. In this study, we describe key characteristics of the healthy and ABU urine microbiomes utilizing 16S rRNA gene (16S rDNA) sequencing and metaproteomics, with the future goal of utilizing this information to personalize the treatment of UTI based on key individual characteristics. Methods
A cross-sectional study of 26 healthy controls and 27 healthy subjects at risk for ABU due to spinal cord injury-related neuropathic bladder (NB) was conducted. Of the 27 subjects with NB, 8 voided normally, 8 utilized intermittent catheterization, and 11 utilized indwelling Foley urethral catheterization for bladder drainage. Urine was obtained by clean catch in voiders, or directly from the catheter in subjects utilizing catheters. Urinalysis, urine culture and 16S rDNA sequencing were performed on all samples, with metaproteomic analysis performed on a subsample. Results
A total of 589454 quality-filtered 16S rDNA sequence reads were processed through a NextGen 16S rDNA analysis pipeline. Urine microbiomes differ by normal bladder function vs. NB, gender, type of bladder catheter utilized, and duration of NB. The top ten bacterial taxa showing the most relative abundance and change among samples were Lactobacillales, Enterobacteriales, Actinomycetales, Bacillales, Clostridiales, Bacteroidales, Burkholderiales, Pseudomonadales, Bifidobacteriales and Coriobacteriales. Metaproteomics confirmed the 16S rDNA results, and functional human protein-pathogen interactions were noted in subjects where host defenses were initiated. Conclusions
Counter to clinical belief, healthy urine is not sterile. The healthy urine microbiome is characterized by a preponderance of Lactobacillales in women and Corynebacterium in men. The presence and duration of NB and method of urinary catheterization alter the healthy urine microbiome. An integrated approach of 16S rDNA sequencing with metaproteomics improves our understanding of healthy urine and facilitates a more personalized approach to prevention and treatment of infection
Action of Natural Abscisic Acid Precursors and Catabolites on Abscisic Acid Receptor Complexes
The Monitor project: JW 380 -- a 0.26, 0.15 Msol pre main sequence eclipsing binary in the Orion Nebula Cluster
We report the discovery of a low-mass (0.26 +/- 0.02, 0.15 +/- 0.01 Msol)
pre-main-sequence eclipsing binary with a 5.3 day orbital period. JW 380 was
detected as part of a high-cadence time-resolved photometric survey (the
Monitor project) using the 2.5m Isaac Newton Telescope and Wide Field Camera
for a survey of a single field in the Orion Nebula Cluster (ONC) region in V
and i bands. The star is assigned a 99 per cent membership probability from
proper motion measurements, and radial velocity observations indicate a
systemic velocity within 1 sigma of that of the ONC. Modelling of the combined
light and radial velocity curves of the system gave stellar radii of 1.19 +0.04
-0.18 Rsol and 0.90 +0.17 -0.03 Rsol for the primary and secondary, with a
significant third light contribution which is also visible as a third peak in
the cross-correlation functions used to derive radial velocities. The masses
and radii appear to be consistent with stellar models for 2-3 Myr age from
several authors, within the present observational errors. These observations
probe an important region of mass-radius parameter space, where there are
currently only a handful of known pre-main-sequence eclipsing binary systems
with precise measurements available in the literature.Comment: 11 pages, 9 figures, accepted for publication in MNRA
- …