99 research outputs found
Wetland Connectivity and Macroinvertebrate Diversity
Wetlands are important in filtering pollutants from aquatic ecosystems and also serve as habitats for a diverse array of organisms. However, wetland-river networks are often subject to human disturbances such as dyke construction. These decreases in connectivity have the potential to impede movement of organisms and nutrients between habitats.
This study examined how the food web structure and diversity of macroinvertebrate communities differ between wetland sites connected and disconnected to nearby rivers. According to macroinvertebrate surveys in wetlands connected to nearby rivers and dyked wetlands (not connected to nearby rivers), there is an increase in average species richness and diversity (Shannon index) in connected sites. This may be because wetland-river connections provide opportunities for species to enter adjacent ecosystems. I used stable isotope analyses to examine the impact of species diversity and connectivity on the nutrient source and trophic position of odonates (dragonflies and damselflies)- top predators in many wetlands. Because stable nitrogen isotope values (δ15N) increase by 3-5 ‰ with each trophic transfer, the offset in δ15N between odonates and amphipods (primary consumers in wetland food webs) served as a proxy for food chain length. Although there was not evidence to conclude that the offset in δ15 N is greater in connected wetlands, average Odonate δ15N values in sites connected to a river were higher than in dyked sites. This observed shift in δ15N may be an indication of different nitrogen inputs to connected and disconnected wetlands, specifically, the relative input of terrestrial (allochthonous) nutrients. Notably, amphipods are often assumed to be primary consumers in wetlands. However, amphipods in this study had variable δ15N values, providing evidence for the claim that they can function as both primary consumers and secondary-tertiary consumers.
While managers increasingly promote the restoration of natural connectivity between wetlands and rivers, there are few studies showing the likely impacts to wetland food web structure. My research will help to fill this gap and provide a more solid foundation for management decisions aimed at preserving wetland biodiversity
Development of a Modified Cervical Collar to Eliminate Overheating and Dysphagia Side Effects
Currently, thousands of people each year require the use of a rigid cervical collar. The collars are used in situations of emergency, as well as in situations of precaution, when spinal injury is or may be present. There are many different styles and sizes of cervical collars available on the market today; however, common side effects are noticed when wearing the collars that may reduce the effectiveness to the patient. Often patients complain of general discomfort issues or may suffer from more serious side effects such as pressure sores, increased intracranial pressure, dysphagia, and abnormal distraction within the upper spine. A need exists for the modification of current cervical collars to reduce the painful or uncomfortable side effects associated with wearing them which would, in turn, increase the effectiveness of the therapy that the collar provides to the spine.
There are two main components of most cervical collar designs: the rigid outer shell and the inner padding. Both of these components have been considered by our design team in the modification design to improve the efficacy of the cervical collar and to reduce side effects from wearing them. The main goals of this project were to reduce the overall discomfort patients experience that is associated with overheating and dysphagia side effects. As a team, we have researched and tested many materials to determine the best fit for our modified cervical collar. The tests included an end user survey that determined the overall comfortability between the available collars, a cold temperature retention test that showed how long the prospective cooling materials would maintain lower temperatures, and an in-collar temperature test that looked at the temperatures of the materials within the lining of a collar
As a team, we have designed a rigid cervical collar that utilizes a slightly flexible, but durable 1/16th inch polyethylene outer shell with padded gel inserts. The outer shell is a two piece design that incorporates the favorable concepts of currently manufactured collars. The two pieces were cut using a scroll saw and molded using an application of heat to the desired positions. There are multiple cut outs in the plastic of both pieces that give flexibility when fitting the collar and the pieces can be connected using velcro straps. The inner “cooling system” is composed of two hydrogels: TheraPearl Technology freezable beads and a pressure activated cooling pad marketed by The Green Pet Shop. The cooling materials will then be wrapped together in polyolefin shrink wrap and placed within specified cutout positions in the antimicrobial padding. Finally the components will be covered in a heat resistant cloth material to ensure direct contact with the skin is compatible and comfortable for the patient. The modifications focus on reducing the hot spots on the cheeks, chin, and neck that are commonly associated with discomfort in patients, will address the discomfort of the chin and neck associated with dysphagia, and will also maintain the rigidity and restriction of motion necessary of the collar. Testing on the efficacy of the design concepts brought forth is still in progress, but we believe the modified cervical collar can increase patient comfort levels and reduce overheating
Posture and Pull Pressure by Horses When Eating Hay or Haylage from a Hay Net Hung at Various Positions
These studies assessed the pressure forces exerted by horses to extract forage from haynets. Study 1 measured horse posture and pressure in Newtons (10 N = 1 kg Force) exerted on haynets when feeding from either a single (SH) or double layered (DH) haynet (3 kg Hay), hung low or high. Mean and maximum pull forces were higher for the DH vs. SH (DH: 81 ± 2 N, max 156 N; SH: 74 ± 2.9 N, max 121 N; p < 0.01). Horses pulled harder on low (max pull 144 ± 8 N) compared to high (109 ± 8 N; p < 0.05) hung haynets. Mean maximum angles (nose-poll-withers) recorded were 90° ± 9 for SH and 127° ± 10 for DH (p < 0.01). Study 2 was a latin square design measuring forces exerted by 10 horses when eating from haynets (6 kg fill) with hay or haylage and attached to the wall at single or double points. Pull pressures were significantly higher when eating haylage compared to hay (mean: 7.5 kg vs. 2 kg and max: 32 kg versus 12 kg, respectively, (p < 0.001). Forage type and fracture properties had the greatest effect on apprehension rates of hay from haynets. In this study, the majority of force exerted when eating from haynets was below 70 N for hay and for haylage 50% of pulls were higher than 50 N with 8% of pulls above 200 N
Carotenoid skin ornaments as flexible indicators of male foraging behavior in a marine predator: Variation among Mexican colonies of brown booby ( Sula leucogaster )
Carotenoid-dependent ornaments can reflect animals’ diet and foraging behaviors. However, this association should be spatially flexible and variable among populations to account for geographic variation in optimal foraging behaviors. We tested this hypothesis using populations of a marine predator (the brown booby, Sula leucogaster) that forage across a gradient in ocean depth in and near the Gulf of California. Specifically, we quantified green chroma for two skin traits (foot and gular color) and their relationship to foraging location and diet of males, as measured via global positioning system tracking and stable carbon isotope analysis of blood plasma. Our three focal colonies varied in which foraging attributes were linked to carotenoid-rich ornaments. For gular skin, our data showed a shift from a benthic prey-green skin association in the shallow waters in the north to a pelagic prey-green skin association in the deepest waters to the south. Mean foraging trip duration and distance of foraging site from coast also predicted skin coloration in some colonies. Finally, brown booby colonies varied in which trait (foot versus gular skin color) was associated with foraging metrics. Overall, our results indicate that male ornaments reflect quality of diet and foraging–information that may help females select mates who are adapted to local foraging conditions and therefore, are likely to provide better parental care. More broadly, our results stress that diet-dependent ornaments are closely linked to animals’ environments and that we cannot assume ornaments or ornament signal content are ubiquitous within species, even when ornaments appear similar among populations
Habitual dietary nitrate intake and cognition in the Australian Imaging, Biomarkers and Lifestyle Study of ageing: A prospective cohort study
Background & aims Dietary nitrate improves cardiovascular health via a nitric oxide (NO) pathway. NO is key to both cardiovascular and brain health. There is also a strong association between vascular risk factors and brain health. Dietary nitrate intake could therefore be associated with better cognitive function and reduced risk of cognitive decline. This is yet to be investigated. The aim of this study was to investigate the association between habitual intake of dietary nitrate from sources where nitrate is naturally present, and cognitive function, and cognitive decline, in the presence or absence of the apolipoprotein E (APOE) ε4 allele. Methods The study included 1254 older adult participants of the Australian Imaging, Biomarkers and Lifestyle Study of Ageing who were cognitively normal at baseline. Plant-derived, vegetable-derived, animal derived nitrate (not including meat where nitrate is an allowed additive), and total nitrate intakes were calculated from baseline food frequency questionnaires using comprehensive nitrate databases. Cognition was assessed at baseline and every 18 months over a follow-up period of 126 months using a comprehensive neuropsychological test battery. Multivariable-adjusted linear mixed effect models were used to examine the association between baseline nitrate intake and cognition over the 126 months (median [IQR] follow-up time of 36 [18–72] months), stratified by APOE ε4 carrier status. Results In non APOE ε4 carriers, for every 60 mg/day higher intake of plant-derived nitrate at baseline there was an associated higher language score [β (95% CI): 0.10 (0.01, 0.19)] over 126 months, after multivariable adjustments. In APOE ε4 carriers, there was an associated better episodic recall memory [0.24 (0.08, 0.41)] and recognition memory [0.15 (0.01, 0.30)] scores. Similar associations were seen for the intakes of vegetable-derived and total nitrate. Additionally, in APOE ε4 carriers, for every 6 mg/day higher intake of animal-derived nitrate (excluding meat with nitrate as an allowed additive) at baseline there was an associated higher executive function score [β (95% CI): 1.41 (0.42, 2.39)]. We did not find any evidence of an association between dietary nitrate intake and rate of cognitive decline. Conclusion Our results suggest that habitual intake of dietary nitrate from sources where nitrate is naturally present impacts cognitive performance in an APOE genotype contingent manner. Further work is needed to validate our findings and understand potential mechanisms underlying the observed effects
The Global Garden project: Imagining plant science
Plants are rich sources of drugs and other high-value chemicals that are used by humans. Many of the plant species that produce important molecules grow in remote locations and have extensive histories of indigenous use. Global concerns about sustainable supply have in some cases led to the development of alternative methods for production using biotechnological approaches. Consideration of responsible stewardship and use of the world's plants and associated traditional knowledge for the greater human good are at the heart of the Convention on Biological Diversity and the recently implemented Nagoya Protocol. The development of fora that enable open discussion and exploration of issues relating to these aspects will be critical in endeavors to protect and preserve both the environment and present and future generations. Summary: Here, we investigate the application of cross-disciplinary approaches to explore societal perceptions of plants and their uses, focusing on high-value chemicals. The Global Garden project engages the public, researchers, and regulators in day-long workshops that combine science, poetry, and visual arts practice to foster participants’ skill in imagining and re-imagining relationships between high-value plant products, biotechnology, and social and ethical aspects of these. The project represents an intervention into discussions of science communications and public engagement, addressing the uses and benefits of arts-based approaches to foster imaginative engagement with plant science. The workshop reported here began with real plant case studies and a discussion of the aims of scientists using them. Participants were invited to respond to the issues of relationships among plants, chemicals, and people raised by the case studies through poetry and visual artwork. The poems and artwork that were produced show variation in the participants’ imaginings of plant science. They present distinctive visions of research and innovation and of the associated ethical and social implications. This type of forum, based on creative immersion, opens up opportunities for engaging with and exploring complex relations between plant biotechnology, society, and ethics. This article offers a reflection on the uses, challenges, and implications of arts-based approaches to research communications and public engagement that disrupts traditional knowledge transfer structures. In doing so, we frame the project within science communication pedagogies and consider public engagement a form of pedagogy
Aquaporin-1 Regulates Platelet Procoagulant Membrane Dynamics and In Vivo Thrombosis
In response to collagen stimulation, platelets use a coordinated system of fluid entry to undergo membrane ballooning, procoagulant spreading, and microvesiculation. We hypothesized that water entry was mediated by the water channel aquaporin-1 (AQP1) and aimed to determine its role in the platelet procoagulant response and thrombosis. We established that human and mouse platelets express AQP1 and localize to internal tubular membrane structures. However, deletion of AQP1 had minimal effects on collagen-induced platelet granule secretion, aggregation, or membrane ballooning. Conversely, procoagulant spreading, microvesiculation, phosphatidylserine exposure, and clot formation time were significantly diminished. Furthermore, in vivo thrombus formation after FeCl3 injury to carotid arteries was also markedly suppressed in AQP1-null mice, but hemostasis after tail bleeding remained normal. The mechanism involves an AQP1-mediated rapid membrane stretching during procoagulant spreading but not ballooning, leading to calcium entry through mechanosensitive cation channels and a full procoagulant response. We conclude that AQP1 is a major regulator of the platelet procoagulant response, able to modulate coagulation after injury or pathologic stimuli without affecting other platelet functional responses or normal hemostasis. Clinically effective AQP1 inhibitors may therefore represent a novel class of antiprocoagulant antithrombotics
Epilepsy and mental retardation limited to females: an under-recognized disorder
Epilepsy and Mental Retardation limited to Females (EFMR) which links to Xq22 has been reported in only one family. We aimed to determine if there was a distinctive phenotype that would enhance recognition of this disorder.We ascertained four unrelated families (two Australian, two Israeli) where seizures in females were transmitted through carrier males. Detailed clinical assessment was performed on 58 individuals, using a validated seizure questionnaire, neurological examination and review of EEG and imaging studies. Gene localization was examined using Xq22 microsatellite markers. Twenty-seven affected females had a mean seizure onset of 14 months (range 6^36) typically presenting with convulsions. All had convulsive attacks at some stage, associated with fever in 17 out of 27 (63%). Multiple seizure types occurred including tonic-clonic (26), tonic (4), partial (11), absence (5), atonic (3) and myoclonic (4). Seizures ceased at mean 12 years. Developmental progress varied from normal (7), to always delayed (4) to normal followed by regression (12). Intellect ranged from normal to severe intellectual disability (ID), with 67% of females having ID or being of borderline intellect. Autistic (6), obsessive (9) and aggressive (7) features were prominent. EEGs showed generalized and focal epileptiform abnormalities. Five obligate male carriers had obsessional tendencies. Linkage to Xq22 was confirmed (maximum lod 3.5 at h = 0).We conclude that EFMR is a distinctive, under-recognized familial syndrome where girls present with convulsions in infancy, often associated with intellectual impairment and autistic features. The unique inheritance pattern with transmission by males is perplexing. Clinical recognition is straightforward in multiplex families due to the unique inheritance pattern; however, this disorder should be considered in smaller families where females alone have seizures beginning in infancy, particularly in the setting of developmental delay. In single cases, diagnosis will depend on identification of the molecular basis. Keywords: epilepsy; intellectual disability; females; X-linked inheritance; autistic features Abbreviations: BAC = bacterial artificial chromosome; CFNS = craniofrontonasal syndrome; EFMR = epilepsy and mental retardation limited to females; ID = intellectual disability
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