Leelanau County Inland Lakes Project

Master of ScienceLandscape ArchitectureUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/114606/2/39015043175614.pd

The Black River: a comprehensive study of physical and chemical characteristics and their potential management implications.

An analysis of the Black River's biological and physicochemical characteristics was conducted for comparison to the model proposed by the river continuum theory. The theory specifies that the biological fauna, physical characteristics and chemical composition observed, are reflected in river order changes in terms of the presence, absence, or density of producer and consumer communities. The study reflected consistencies between the model and observed physical parameters and chemical attributes, but biological indicators were less corroborating. Physical characteristics such as temperature, depth, width, velocity, discharge, and suspended sediments increased with river mile and trends in the data became apparent. Chemical factors such as nitrates, dissolved oxygen, pH, alkalinity, and hardness, though not as clearly conclusive, show a gradient associated with river order transition. Biological indicators were not as conclusive in supporting the river continuum theory since there was no representation of shredders in the headwaters and predatory species were found at most sites. Management issues of the Black River address the control of soil erosion, species composition, and sedimentation as well as maintaining water temperature.http://deepblue.lib.umich.edu/bitstream/2027.42/54342/1/2778.pd

Uszkodzenie nadnerczy w następstwie tępych urazów: wskaźnik ciężkości doznanych obrażeń

Introduction: Adrenal gland injuries (AGI) are seen increasingly frequently owing to advances in modern imaging techniques. This study describes a series of patients with blunt AGI, with the emphasis on AGI as a marker of injury severity, CT-radiographic classification of AGI and associated injury patterns. Material and methods: A retrospective review of blunt trauma patients with AGI was performed. Variables examined included demographics, mechanism of injury, length of hospital and ICU stay, clinical status on admission, AGI characteristics, associated injuries, complications, procedures, mortality and discharge disposition. Results: There were 29 AGI patients with a mean injury severity score of 25. The most common injury mechanisms were motor-vehicular collisions (15/29) and falls (5/29). Right-sided AGI (16/29) outnumbered left-sided (12/29) injuries. The most common CT-radiographic types of AGI were adrenal gland contusions and lacerations with limited "blush". While patterns of injuries differed between right and left-sided AGI, the mean number of injuries did not. The most common associated injuries included extremity (21/29), rib (20/29) and spinal fractures (18/29). Common procedures included orthopaedic fixation (10/29), vena cava filter (8/29) and tracheostomy (5/29). A median of two complications per patient was reported, including adrenal insufficiency in two patients. Mortality was 17%. The median hospital and ICU length of stay were 15 and 12 days, respectively. Conclusions: Adrenal gland injury is associated with significant morbidity and mortality. With modern imaging modalities capable of reliably detecting adrenal injury, the presence of AGI should be considered a marker of overall injury severity. The authors provide a CT-radiographic classification of adrenal injuries.Wstęp: W związku z postępem w zakresie nowoczesnych metod obrazowania coraz częściej stwierdza się uszkodzenia nadnerczy (AGI, adrenal gland injuries). W tym badaniu opisano grupę chorych, którzy doznali uszkodzenia nadnerczy w wyniku tępego urazu. Zwrócono szczególną uwagę na AGI jako wskaźnik ciężkości odniesionych obrażeń, klasyfikację AGI na podstawie tomografii komputerowej i charakter współistniejących obrażeń. Materiał i metody: Przeprowadzono retrospektywną analizę danych pacjentów, którzy doznali AGI w wyniku tępego urazu. W badaniu uwzględniono dane demograficzne, mechanizm powstania urazu, czas hospitalizacji oraz pobytu na oddziale intensywnej opieki medycznej, stan kliniczny w chwili przyjęcia do szpitala, cechy AGI, doznane obrażenia, powikłania, zastosowane procedury medyczne, odsetek zgonów i dalsze postępowanie. Wyniki: Do badania włączono 29 osób z AGI, u których średnia ocena ciężkości obrażeń wynosiła 25. Najczęstszymi przyczynami urazu były wypadki motocyklowe (15/29) i upadki (5/29). Liczba prawostronnych AGI (16/29) była wyższa niż liczba uszkodzeń lewostronnych (12/29). Najczęściej stwierdzanym rodzajem uszkodzeń AGI w badaniu tomograficznym było stłuczenie i rozdarcie narządu z niewielkim krwawieniem. Chociaż charakter uszkodzeń różnił się w zależności od prawo- lub lewostronnej lokalizacji AGI, średnia liczba uszkodzeń była taka sama. Najczęstszymi współwystępującymi obrażeniami były złamania kończyn (21/29), żeber (20/29) i kręgów (18/29). Do najczęściej wykonywanych procedur należały: unieruchomienie ortopedyczne (10/29), wszczepienie filtra do żyły głównej (8/29) i tracheostomia (5/29). Mediana liczby powikłań u poszczególnych chorych wynosiła 2 (włączając niewydolność nadnerczy u 2 osób). Odsetek zgonów wynosił 17%. Mediana okresu hospitalizacji i pobytu na oddziale intensywnej opieki medycznej wynosiła odpowiednio 15 i 12 dni. Wnioski: Uszkodzenie nadnerczy wiąże się ze znaczną chorobowością i śmiertelnością. Dostępne obecnie nowoczesne metody obrazowania umożliwiają wykrycie uszkodzeń nadnerczy. Należałoby rozważyć przyjęcie obecności AGI jako markera ciężkości doznanych obrażeń. Autorzy przedstawili klasyfikację uszkodzeń nadnerczy na podstawie badań tomograficznych

Combinatorial Markov chains on linear extensions

We consider generalizations of Schuetzenberger's promotion operator on the set L of linear extensions of a finite poset of size n. This gives rise to a strongly connected graph on L. By assigning weights to the edges of the graph in two different ways, we study two Markov chains, both of which are irreducible. The stationary state of one gives rise to the uniform distribution, whereas the weights of the stationary state of the other has a nice product formula. This generalizes results by Hendricks on the Tsetlin library, which corresponds to the case when the poset is the anti-chain and hence L=S_n is the full symmetric group. We also provide explicit eigenvalues of the transition matrix in general when the poset is a rooted forest. This is shown by proving that the associated monoid is R-trivial and then using Steinberg's extension of Brown's theory for Markov chains on left regular bands to R-trivial monoids.Comment: 35 pages, more examples of promotion, rephrased the main theorems in terms of discrete time Markov chain

Human and great ape red blood cells differ in plasmalogen levels and composition

<p>Abstract</p> <p>Background</p> <p>Plasmalogens are ether phospholipids required for normal mammalian developmental, physiological, and cognitive functions. They have been proposed to act as membrane antioxidants and reservoirs of polyunsaturated fatty acids as well as influence intracellular signaling and membrane dynamics. Plasmalogens are particularly enriched in cells and tissues of the human nervous, immune, and cardiovascular systems. Humans with severely reduced plasmalogen levels have reduced life spans, abnormal neurological development, skeletal dysplasia, impaired respiration, and cataracts. Plasmalogen deficiency is also found in the brain tissue of individuals with Alzheimer disease.</p> <p>Results</p> <p>In a human and great ape cohort, we measured the red blood cell (RBC) levels of the most abundant types of plasmalogens. Total RBC plasmalogen levels were lower in humans than bonobos, chimpanzees, and gorillas, but higher than orangutans. There were especially pronounced cross-species differences in the levels of plasmalogens with a C16:0 moiety at the <it>sn</it>-1 position. Humans on Western or vegan diets had comparable total RBC plasmalogen levels, but the latter group showed moderately higher levels of plasmalogens with a C18:1 moiety at the <it>sn</it>-1 position. We did not find robust sex-specific differences in human or chimpanzee RBC plasmalogen levels or composition. Furthermore, human and great ape skin fibroblasts showed only modest differences in peroxisomal plasmalogen biosynthetic activity. Human and chimpanzee microarray data indicated that genes involved in plasmalogen biosynthesis show cross-species differential expression in multiple tissues.</p> <p>Conclusion</p> <p>We propose that the observed differences in human and great ape RBC plasmalogens are primarily caused by their rates of biosynthesis and/or turnover. Gene expression data raise the possibility that other human and great ape cells and tissues differ in plasmalogen levels. Based on the phenotypes of humans and rodents with plasmalogen disorders, we propose that cross-species differences in tissue plasmalogen levels could influence organ functions and processes ranging from cognition to reproduction to aging.</p

Identification of differences in human and great ape phytanic acid metabolism that could influence gene expression profiles and physiological functions

<p>Abstract</p> <p>Background</p> <p>It has been proposed that anatomical differences in human and great ape guts arose in response to species-specific diets and energy demands. To investigate functional genomic consequences of these differences, we compared their physiological levels of phytanic acid, a branched chain fatty acid that can be derived from the microbial degradation of chlorophyll in ruminant guts. Humans who accumulate large stores of phytanic acid commonly develop cerebellar ataxia, peripheral polyneuropathy, and retinitis pigmentosa in addition to other medical conditions. Furthermore, phytanic acid is an activator of the PPAR-alpha transcription factor that influences the expression of genes relevant to lipid metabolism.</p> <p>Results</p> <p>Despite their trace dietary phytanic acid intake, all great ape species had elevated red blood cell (RBC) phytanic acid levels relative to humans on diverse diets. Unlike humans, chimpanzees showed sexual dimorphism in RBC phytanic acid levels, which were higher in males relative to females. Cultured skin fibroblasts from all species had a robust capacity to degrade phytanic acid. We provide indirect evidence that great apes, in contrast to humans, derive significant amounts of phytanic acid from the hindgut fermentation of plant materials. This would represent a novel reduction of metabolic activity in humans relative to the great apes.</p> <p>Conclusion</p> <p>We identified differences in the physiological levels of phytanic acid in humans and great apes and propose this is causally related to their gut anatomies and microbiomes. Phytanic acid levels could contribute to cross-species and sex-specific differences in human and great ape transcriptomes, especially those related to lipid metabolism. Based on the medical conditions caused by phytanic acid accumulation, we suggest that differences in phytanic acid metabolism could influence the functions of human and great ape nervous, cardiovascular, and skeletal systems.</p

Allelic Expression Imbalance Promoting a Mutant PEX6 Allele Causes Zellweger Spectrum Disorder

Zellweger spectrum disorders (ZSDs) are autosomal-recessive disorders that are caused by defects in peroxisome biogenesis due to bi-allelic mutations in any of 13 different PEX genes. Here, we identified seven unrelated individuals affected with an apparent dominant ZSD in whom a heterozygous mutant PEX6 allele (c.2578C&gt;T [p.Arg860Trp]) was overrepresented due to allelic expression imbalance (AEI). We demonstrated that AEI of PEX6 is a common phenomenon and is correlated with heterozygosity for a frequent variant in the 3' untranslated region (UTR) of the mutant allele, which disrupts the most distal of two polyadenylation sites. Asymptomatic parents, who were heterozygous for PEX c.2578C&gt;T, did not show AEI and were homozygous for the 3' UTR variant. Overexpression models confirmed that the overrepresentation of the pathogenic PEX6 c.2578T variant compared to wild-type PEX6 c.2578C results in a peroxisome biogenesis defect and thus constitutes the cause of disease in the affected individuals. AEI promoting the overrepresentation of a mutant allele might also play a role in other autosomal-recessive disorders, in which only one heterozygous pathogenic variant is identified.</p

Canine Hereditary Ataxia in Old English Sheepdogs and Gordon Setters Is Associated with a Defect in the Autophagy Gene Encoding RAB24

Old English Sheepdogs and Gordon Setters suffer from a juvenile onset, autosomal recessive form of canine hereditary ataxia primarily affecting the Purkinje neuron of the cerebellar cortex. The clinical and histological characteristics are analogous to hereditary ataxias in humans. Linkage and genome-wide association studies on a cohort of related Old English Sheepdogs identified a region on CFA4 strongly associated with the disease phenotype. Targeted sequence capture and next generation sequencing of the region identified an A to C single nucleotide polymorphism (SNP) located at position 113 in exon 1 of an autophagy gene, RAB24, that segregated with the phenotype. Genotyping of six additional breeds of dogs affected with hereditary ataxia identified the same polymorphism in affected Gordon Setters that segregated perfectly with phenotype. The other breeds tested did not have the polymorphism. Genome-wide SNP genotyping of Gordon Setters identified a 1.9 MB region with an identical haplotype to affected Old English Sheepdogs. Histopathology, immunohistochemistry and ultrastructural evaluation of the brains of affected dogs from both breeds identified dramatic Purkinje neuron loss with axonal spheroids, accumulation of autophagosomes, ubiquitin positive inclusions and a diffuse increase in cytoplasmic neuronal ubiquitin staining. These findings recapitulate the changes reported in mice with induced neuron-specific autophagy defects. Taken together, our results suggest that a defect in RAB24, a gene associated with autophagy, is highly associated with and may contribute to canine hereditary ataxia in Old English Sheepdogs and Gordon Setters. This finding suggests that detailed investigation of autophagy pathways should be undertaken in human hereditary ataxia.American Kennel Club Canine Health Foundation (grant CHF 0407)American Kennel Club Canine Health Foundation (grant CHF 0925)Old English Sheepdog Club of AmericaTarTan Gordon Setter ClubEuropean Science Foundation (EURYI)Canine Health Information Center (DNA Repository

Proximity effect at superconducting Sn-Bi2Se3 interface

We have investigated the conductance spectra of Sn-Bi2Se3 interface junctions down to 250 mK and in different magnetic fields. A number of conductance anomalies were observed below the superconducting transition temperature of Sn, including a small gap different from that of Sn, and a zero-bias conductance peak growing up at lower temperatures. We discussed the possible origins of the smaller gap and the zero-bias conductance peak. These phenomena support that a proximity-effect-induced chiral superconducting phase is formed at the interface between the superconducting Sn and the strong spin-orbit coupling material Bi2Se3.Comment: 7 pages, 8 figure