Landscape features may restricting dispersal and gene flow, and increase demographic isolation among sub-populations. In addition, landscape features may represent potential dispersal barriers ...depending on species vagility. To predict the persistence of populations and to formulate adequate conservation measures it is essential to understand the ability of species to transverse landscape barriers. Using population genetic techniques we assessed the importance of physical barriers along the Kinabatangan River for a suite of non-volant small mammals.
Cytochrome b
sequence variation was examined for each of the 19 species sampled across both riverbanks. Haplotype networks and molecular variance analyses indicated contrasting patterns of genetic isolation between riversides for different taxa. Genetic isolation between riversides ranged from moderate to complete in tree shrews and squirrels, whereas no isolating effect could be detected in murids and gymnures. Although genetic divergence between forest fragments on the same side of the river could only be studied in a subset of six species, the results suggest an additional dispersal barrier for two of these studied species. While barrier effects of a paved road and tributaries could not be verified, large oil palm plantations seem to have disrupted gene flow in these species. Furthermore, the findings suggest higher genetic connectivity on the more continuously forested compared to the more fragmented riverside, and underline the importance of forest corridors as essential conservation measures to maintain genetic diversity in a fragmented landscape such as that along the Kinabatangan River.
Constraints in migratory capabilities, such as the disruption of gene flow and genetic connectivity caused by habitat fragmentation, are known to affect genetic diversity and the long-term ...persistence of populations. Although negative population trends due to ongoing forest loss are widespread, the consequence of habitat fragmentation on genetic diversity, gene flow and genetic structure has rarely been investigated in Bornean small mammals. To fill this gap in knowledge, we used nuclear and mitochondrial DNA markers to assess genetic diversity, gene flow and the genetic structure in the Bornean tree shrew, Tupaia longipes, that inhabits forest fragments of the Lower Kinabatangan Wildlife Sanctuary, Sabah. Furthermore, we used these markers to assess dispersal regimes in male and female T. longipes.
In addition to the Kinabatangan River, a known barrier for dispersal in tree shrews, the heterogeneous landscape along the riverbanks affected the genetic structure in this species. Specifically, while in larger connected forest fragments along the northern riverbank genetic connectivity was relatively undisturbed, patterns of genetic differentiation and the distribution of mitochondrial haplotypes in a local scale indicated reduced migration on the strongly fragmented southern riverside. Especially, oil palm plantations seem to negatively affect dispersal in T. longipes. Clear sex-biased dispersal was not detected based on relatedness, assignment tests, and haplotype diversity.
This study revealed the importance of landscape connectivity to maintain migration and gene flow between fragmented populations, and to ensure the long-term persistence of species in anthropogenically disturbed landscapes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Sound categorisation plays a crucial role for processing ecological and social stimuli in a species’ natural environment. To explore the discrimination and evaluation of sound stimuli in human babies ...and nonhuman primates, a reciprocal habituation-dishabituation paradigm has been successfully introduced into auditory research. We applied the reciprocal paradigm for the first time to a non-primate mammal, the tree shrew (
Tupaia belangeri
), to examine to what extent non-primate mammals share the ability to evaluate communication calls with primates. Playback stimuli were three types of communication calls, differing distinctively in context and acoustic structure, as well as two artificial control sounds, differing solely in frequency. We assessed the attention towards the playback stimuli by the latency to respond to the test stimulus. Subjects evaluated pairs of communication call types as well as the artificial playback stimuli. Attention towards the test stimuli differed significantly in strength for one pair of communication calls, with subjects dishabituating faster to one category than the other. The comparison of a second pair of communication calls did not show significant differences. Interestingly, subjects also evaluated the artificial control sounds. Findings are only partly in line with results on human and non-human primates. They provided first evidence that in non-primate mammals acoustic evaluation is not solely affected by the sound-associated context but is also linked to unusualness and acoustic cues, such as peak frequency.
Social functioning deficits are clinically and theoretically important characteristics of schizophrenia, as is evidenced by their prevalence, relative stability, and severity in post-onset ...schizophrenic patients. In addition, some evidence suggests that pre-onset schizophrenic patients and the biological relatives of schizophrenic patients may also exhibit social deficits. These findings suggest that social functioning deficits may serve as indicators of the development of above-threshold liability for schizophrenia among preschizophrenic patients, and as indicators of below-threshold liability for schizophrenia among their non-schizophrenic, biological relatives. To explore these hypotheses, the childhood and adolescence social functioning characteristics of 74 stable schizophrenic outpatients, 49 of the nonschizophrenic siblings of schizophrenic patients, 63 screened control probands, and 63 of the unscreened siblings of control probands were assessed. All subjects' retrospectively recalled social functioning was blindly assessed from videotaped structured interviews (Premorbid Adjustment Scale; Cannon-Spoor, Potkin, & Wyatt, 1982). Subjects' lifetime psychopathology was also assessed with the Schedule for Affective Disorders and Schizophrenia (SADS-L; Endicott & Spitzer, 1978), and either the original or revised version of the Structured Interview for DSM-III(R) Personality Disorders (SIDP, Pfohl, Stangl, & Zimmerman, 1982; or SIDP-R, Pfohl, Blum, Zimmerman, & Stangl, 1989). Two key findings were obtained. First, the pre-onset childhood and adolescence social functioning of the schizophrenic patients was significantly poorer than that of the other three subject groups. This finding supported the hypothesis that social functioning impairments are associated with the development of eventual above-threshold liability for schizophrenia among pre-onset schizophrenic patients, and specifically favored the early onset models of the development of above-threshold liability for schizophrenia at least for a subset of patients. Second, the results were more complex and inconclusive regarding childhood and adolescence social functioning deficits among the siblings of schizophrenic patients. Based on these data, it is less likely that social functioning deficits serve as useful behavioral indicators of below-threshold liability for schizophrenia among the siblings of schizophrenic patients.
To study ground reaction forces (GRF) and temporospatial parameters for small and medium size dogs using a pressure sensitive walkway (PSW). We hypothesized that, at a given speed, small dogs would ...have shorter stance time than medium dogs and that dog height (DH) would influence GRF.
30 healthy, sound dogs were divided into 2 groups, small < 15 kg and medium dog group weighing 15 to 25 kg.
GRFs were measured for both groups at walk and trot using PSW. Muscle mass and joint angles were measured. Data were analyzed using SAS version 9.4. Two groups were compared using 2-sample t test, Wilcoxon rank sum test, and Fisher exact test.
GRFs were successfully measured in both dog groups for walk and trot. Medium dogs had larger limb girth, more peak pressure, max force, increased stance, swing time, and larger stride length compared with small dogs. Stance time increased as DH increased at walk and trot (r = 0.854, P < .001; r = 0.876, P < .001). Stance time increased as BW (body weight) increased at walk and trot (r = 0.887, P < .001; r = 0.858 P < .001). Inconclusive data was obtained for stride acceleration and velocity. The handler side did not influence results (P > .05). Range of motion (ROM) did not differ among groups.
Results suggested that PSW is a reliable device for small and medium dogs. At walk and at a trot, GRF are smaller in small dogs compared with medium dogs, suggesting that normal reference data for PSW need to take BW and DH into account.
To evaluate the effect of variable centrifugation protocols on the cellular composition of the final product of a canine autologous conditioned plasma double-syringe system.
30 client-owned healthy ...adult medium- to large-breed (17- to 45-kg) dogs.
35 mL of anticoagulated whole blood from each subject was aliquoted into 3 samples: a baseline and 2 double syringes. The syringes were processed for platelet-rich plasma (PRP). Each double syringe was randomly assigned to 1 of 5 groups, which varied in centrifugation settings between 580 and 1,304 X g and 5 and 10 minutes. CBC analysis was performed on each of the samples to determine cellular composition. A mixed-effect linear model was fit to the data.
60 PRP samples and 30 whole blood samples were analyzed. Manufacturer settings generated a platelet fold change > 1 but did not increase concentration to the extent expected. When comparing speed alone, increased centrifugation force was associated with lower platelet fold change. When comparing time alone, increased centrifugation time was also associated with lower platelet fold change and lower leukocyte concentration.
Autologous conditioned plasma double syringes require a low volume of initial whole blood, making them preferable for canine PRP in clinical settings. This study aimed to evaluate the effect of the centrifugation protocol on the final product cellular composition in dogs and add to the available data on protocols to maximize platelet yield in PRP. Due to inherent individual variability, this study emphasized the importance of evaluating biological samples prior to administration to predict and improve patient outcomes.
Candida species are the most common cause of opportunistic fungal infection worldwide. Here we report the genome sequences of six Candida species and compare these and related pathogens and ...non-pathogens. There are significant expansions of cell wall, secreted and transporter gene families in pathogenic species, suggesting adaptations associated with virulence. Large genomic tracts are homozygous in three diploid species, possibly resulting from recent recombination events. Surprisingly, key components of the mating and meiosis pathways are missing from several species. These include major differences at the mating-type loci (MTL); Lodderomyces elongisporus lacks MTL, and components of the a1/2 cell identity determinant were lost in other species, raising questions about how mating and cell types are controlled. Analysis of the CUG leucine-to-serine genetic-code change reveals that 99% of ancestral CUG codons were erased and new ones arose elsewhere. Lastly, we revise the Candida albicans gene catalogue, identifying many new genes.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Water scavenger beetles (Coleoptera: Hydrophilidae) are a broadly distributed group with high extant diversity. However, reliable records from Baltic amber (Eocene) are scarce and limited to two ...undescribed species previously reported in the literature. Here we study these two specimens plus four additional ones. All specimens were sub-optimal in terms of preservation and visibility of their morphology using traditional light microscopy. Opaque bubbles, cracks in the amber pieces and contracted appendages obscured most of the crucial characters, preventing their formal description and making them prone to misidentification. Here we used X-ray micro-computed tomography (μCT) to reconstruct the morphology of the embedded specimens and described three new species: Anacaena morla sp. nov., Crenitis profechuyi sp. nov. and Helochares fog sp. nov. Micro-CT reconstructions allowed us to visualise the morphology of the specimens to an extent where it was possible to hypothesise possible phylogenetic relations of the new taxa as well as the biogeographic implications of these relationships.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
9.
Trace Metals in Host–Microbe Interactions Weiser, Jeffrey N; Schryvers, Anthony B; Murphy, Michael E. P ...
Trace Metals and Infectious Diseases,
06/2015
Book Chapter
Microbes must acquire metals for metabolic processes, with nearly a half of all enzymes requiring a metal cofactor for function, yet microbes can be poisoned by metals. The host innate immune ...defenses are thought to exploit these vulnerabilities to protect against invading pathogens, whereas microbes can respond by employing multiple strategies to maintain their metal homeostasis. Understanding these microbial strategies combined with knowledge of diverse metal challenges faced by different microbes in the various host niches could inform the development of new approaches for combating infectious diseases. This chapter summarizes extensive discussions on the interplay of metal ions in host–microbe interactions, from the microbial perspective. Focus is on five key areas: (a) how we define and determine metal availability, (b) the different levels and sources of metals available to microbes in different niches within the host, (c) the effect of the metal status of a pathogen, as derived from its prior environment, on its ability to establish an infection or the severity of disease, (d) the interplay between metals and the microbiota, and (e) how metal restriction and metal oversupply can kill or inhibit the growth of microbes.
Our discussions addressed the relationship between the metal status of different host niches and the capabilities of different microbes (pathogens and commensals) within these niches to compete for ...metals and avoid metal poisoning in determining disease outcomes. The best understood microbial systems belong to the bacteria and fungi; hence these organisms formed the basis of the discussions. Four background papers to this Forum informed and contributed greatly to our discussions: Lemire et al. (Chapter 2), Bachmann and Weiser (Chapter 3), Loutet et al. (Chapter 4), and Imlay (Chapter 5).
How do we define and determine metal availability in different environments,
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