Increased agricultural production within the Grand Prairie region, USA, has resulted in drainage of most natural wetlands within the landscape. Muskrats (
Ondatra zibethicus
(L., 1766)) in this ...region have shifted much of their distribution to riparian habitats that have unstable flow regimes and flood inundation times that could be related to position within watersheds. We investigated predation risk of radio-marked riparian muskrats during flooding events in relation to landscape position. We used known-fate models and an information-theoretic approach to examine effects of age, season, hydrology, and riparian width on weekly survival rates. During flooding events, muskrats positioned farther from headwaters were displaced for longer, as well as exposed to predation from terrestrial predators for longer, than those positioned closer to headwaters. However, this increased exposure during floods did not translate into lower survival because most mortalities were due to predation by American mink (
Neovison vison
(Schreber, 1777)) along stream edges during nonflooding periods. Weekly survival of muskrats was lower in winter (mean = 0.9377, SE = 0.1793) than in nonwinter (mean = 0.9770, SE = 0.0116) and was positively related to riparian width. Larger riparian buffers can increase muskrat survival in small streams and agricultural ditches within highly altered, human-dominated agroecosystems. Our study provides a rare example of linking riparian buffers to fitness for a stream-associated organism.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Naval Medical Research Center, National Naval Medical Center,
Bethesda, Maryland 20889-5607
Elayan, Ikram M.,
Milton J. Axley,
Paruchuri V. Prasad,
Stephen T. Ahlers, and
Charles R. Auker.
Effect of ...Hyperbaric Oxygen Treatment on Nitric Oxide and Oxygen
Free Radicals in Rat Brain. J. Neurophysiol. 83: 2022-2029, 2000. Oxygen (O 2 ) at high
pressures acts as a neurotoxic agent leading to convulsions. The
mechanism of this neurotoxicity is not known; however, oxygen free
radicals and nitric oxide (NO) have been suggested as contributors.
This study was designed to follow the formation of oxygen free radicals
and NO in the rat brain under hyperbaric oxygen (HBO) conditions using
in vivo microdialysis. Male Sprague-Dawley rats were exposed to 100%
O 2 at a pressure of 3 atm absolute for 2 h. The
formation of 2,3-dihydroxybenzoic acid (2,3-DHBA) as a result of
perfusing sodium salicylate was followed as an indicator for the
formation of hydroxyl radicals. 2,3-DHBA levels in hippocampal and
striatal dialysates of animals exposed to HBO conditions were not
significantly different from controls. However, rats treated under the
same conditions showed a six- and fourfold increase in nitrite/nitrate,
break down products of NO decomposition, in hippocampal and striatal
dialysates, respectively. This increase was completely blocked by the
nitric oxide synthase (NOS) inhibitor L -nitroarginine
methyl ester ( L -NAME). Using neuronal NOS, we determined
the NOS O 2 K m to be 158 ± 28 (SD) mmHg, a value which suggests that production of NO by NOS would
increase approximately four- to fivefold under hyperbaric
O 2 conditions, closely matching the measured increase in
vivo. The increase in NO levels may be partially responsible for some
of the detrimental effects of HBO conditions.
BACKGROUND AND PURPOSE—In patients with ischemic stroke, randomized trials showed a better functional outcome after endovascular therapy with new-generation thrombectomy devices compared with medical ...treatment, including intravenous thrombolysis. However, effects on mortality and the generalizability of results to routine clinical practice are uncertain.
METHODS—In a prospective observational register-based study patients with ischemic stroke treated either with thrombectomy, intravenous thrombolysis, or their combination were included. Primary outcome was the modified Rankin scale score (0 no symptoms to 6 death) at 3 months. Ordinal logistic regression was used to estimate the common odds ratio as treatment effects (shift analysis). Propensity score matching was applied to compare patients treated either with intravenous thrombolysis alone or with intravenous thrombolysis plus thrombectomy.
RESULTS—Among 2650 recruited patients, 1543 received intravenous thrombolysis, 504 underwent thrombectomy, and 603 received intravenous thrombolysis in combination with thrombectomy. Later time-to-treatment was associated with worse outcomes among patients treated with thrombectomy plus thrombolysis. In 241 pairs of propensity score–matched patients with a proximal intracranial occlusion, thrombectomy plus thrombolysis was associated with improved functional outcome (common odds ratio, 1.84; 95% confidence interval, 1.32–2.57), and reduced mortality (15% versus 33%; P<0.0001) compared with intravenous thrombolysis alone. Results were similar in various sensitivity analyses accounting for missing outcome data and different analytic methods.
CONCLUSIONS—Results from this large prospective registry show that also in routine clinical care thrombectomy plus thrombolysis compared with thrombolysis alone improved functional outcome and reduced mortality in patients with ischemic stroke. Earlier treatment was associated with better outcomes.
In recent years, great strides in understanding and regulating the immune system have led to new hope for harnessing its exquisite specificity to destroy cancer cells without affecting normal ...tissues. This review examines the fundamental immunologic advances and the novel vaccine strategies arising from these advances, as well as the early clinical trials studying new approaches to treat or prevent cancer.
Core deficits in autism spectrum disorder (ASD) center around social communication and behavior. For those with ASD, these deficits complicate the task of learning how to cope with and manage complex ...social emotional issues. Although individuals with ASD may receive sufficient academic and basic behavioral support in school settings, supports for dealing with complex social emotional issues are more difficult to access, even though these issues significantly impact student learning. When addressing these challenging social- and emotional-based issues, school and professional personnel need more specific instructional skill sets and resources to effectively and compassionately support students with ASD. In this article, we address three challenging areas of social emotional development that are commonly experienced by individuals with ASD: Anxiety, social isolation, and grief. We briefly explore the existing research on these three topics, identify evidence-based practices and learning strategies to support social emotional learning in individuals with ASD, and include descriptive lists of practical resources that address anxiety, social isolation, and grief.
Effective frontline defenses against HIV-1 will require targeting vaccines to mucosal tissue in order to induce αβ CD8⁺ lymphocytes in mucosal effector sites (lamina propria and intraepithelial ...compartment) as well as antibody secreting plasma cells that can neutralize and limit free virus. A concerted second wave of assault against the virus will require the activation and recruitment of antigen specific memory CD4⁺ and CD8⁺ T cells in mesenteric lymph nodes and distal secondary lymphoid organs. New delivery strategies targeting the "right" DC subsets in combination with delivery of mucosal adjuvants and innate signals for activating DC will be essential for mucosal vaccines in order to circumvent the naturally tolerogenic environment and the induction of Tregs. Mucosal delivery of antigen in combination with inflammatory signals has been shown to empower systemic immunization by directing responses to mucosal sites for imprinting optimum mucosal memory. Here, we discuss novel vaccine strategies and adjuvants for optimizing mucosal delivery of HIV vaccines.
Little is known about men who have not yet committed child sexual abuse but may be at risk of doing so (
potential offenders) and the factors that distinguish these men from undetected child sexual ...abuse offenders with a sexual interest in children (
Dunkelfeld offenders).
The present study describes and compares potential and Dunkelfeld offenders, which can be viewed as ideal target groups for (primary) prevention efforts with respect to child sexual abuse. Also, this study seeks to demonstrate the feasibility of using a telephone screening procedure to conduct research with these groups.
Using a computer assisted telephone interview (CATI), data on demographics, mental health, sexuality, criminal history, and victim characteristics were collected from respondents in a nation-wide media campaign, which informed potential (re-)offenders of child sexual abuse of a research and treatment project.
Many participants reported recurrent sexual fantasies involving minors, as well as related distress, suggesting a high prevalence of pedophilia and hebephilia. More than half feared they would sexually abuse a minor, and Dunkelfeld offenders reported 3.2 victims on average. Group comparisons revealed that Dunkelfeld offenders were, for example, more likely to perceive themselves being at risk of offending, compared to potential offenders.
The results suggest that targeting potential and Dunkelfeld offenders could prove a worthwhile approach in the prevention of child sexual abuse.
Experimental and numerical data for the heat transfer as a function of the Rayleigh, Prandtl, and Rossby numbers in turbulent rotating Rayleigh-Bénard convection are presented. For relatively small ...Ra approximately 10(8) and large Pr modest rotation can enhance the heat transfer by up to 30%. At larger Ra there is less heat-transfer enhancement, and at small Pr less, similar 0.7 there is no heat-transfer enhancement at all. We suggest that the small-Pr behavior is due to the breakdown of the heat-transfer-enhancing Ekman pumping because of larger thermal diffusion.
Purpose
Concern is growing about long-term side effects of differentiated thyroid cancer treatment, most notably radioactive iodine (RAI) therapy. However, published studies on the subject have had ...heterogeneous cohorts and conflicting results. This review seeks to provide an updated evaluation of published evidence, and to elucidate the risk of second primary malignancies (SPMs), especially secondary hematologic malignancies (SHMs), attributable to RAI therapy.
Methods
An extensive literature search was performed in Ovid MEDLINE, Ovid MEDLINE and In-Process & Other Non-Indexed Citations, Ovid MEDLINE Epub Ahead of Print, Cochrane Central Register of Controlled Trials (CENTRAL) and PubMed. Studies regarding RAI-induced SPMs or a dose–response relationship between RAI therapy and SPMs were identified, 10 of which were eligible for the analysis. We evaluated risk of bias in each study and judged quality of evidence (QOE) across all studies using the Grading of Recommendations, Assessment, Development and Evaluations approach.
Results
For the outcome “SPM”, the relative effect (relative risk, hazard ratio, or odds ratio) of RAI vs. no RAI ranged from 1.14 to 1.84 across studies, but most results were not statistically significant. For the outcome “SHM”, reported relative effects ranged from 1.30 to 2.50, with 2/3 of the studies presenting statistically significant results. In 7/8 of the studies, increased risk for SPM was shown with increasing cumulative RAI activity. QOE was “very low” regarding SPM after RAI and regarding a dose–response relationship, and “low” for SHM after RAI.
Conclusion
Based on low quality evidence, an excess risk for the development of SPM cannot be excluded but is expected to be small.
The natural immune response against HIV and other pathogens that cause chronic infection is insufficient for protection. Novel vaccine design and delivery strategies for optimization of HIV vaccines ...are urgently needed. These will require a better understanding of a number of factors including: the interplay between dendritic cells (DCs) and multiple cell types in linking innate signals that orchestrate subsequent adaptive immune responses; the regulation of DC function by viral and bacterial vectors, adjuvants and immunomodulatory molecules; and the temporal and synergistic relationships between C-type lectins, Toll-like receptors, NOD-like receptors and RIG-1-like receptors, chemokines and cytokines in enhancing immune responses. Here, we discuss current vaccine strategies for optimizing the induction of immune responses by the recruitment of DCs and the targeting of vaccine antigens to DCs.
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