Progress Toward the Biochemical Characterization of a Protein Involved in the Production of Microbial Plastics: Asymmetric Synthesis of 3-Hydroxy Fatty Acids

Poly(3-hydroxyalkanoates) (PHAs) are biodegradable polymeric materials that are of interest due to their ability to serve as green alternatives to the less environmentally friendly petroleum-based plastics that populate our modern world. PHAs are produced by various microorganisms from sugar and fatty acid feedstocks, and they are degraded by microorganisms as well. The metabolic fundamentals of the production of PHAs can be investigated through studying the behavior of the protein PP_0763 from the soil bacterium Pseudomonas putida KT2440, which we believe to be involved in the metabolic redirection of intracellular fatty acids toward PHA biosynthesis. PP_0763 has been successfully expressed and purified, and insight can now be gained into the substrate specificity of this protein via biochemical assay. In order to move forward with assay design, in this study we demonstrate our progress towards the synthesis of a panel of enantiopure 3-hydroxy fatty acids via an asymmetric aldol strategy. Once complete, our assay will test the protein’s affinity for 3-hydroxy fatty acids of varying hydrocarbon chain lengths, leading to clarification of the role the protein plays in PHA biosynthesis. Senior Project submitted to The Division of Science, Mathematics and Computing of Bard College

Before You Grow Fruit

Senior Project submitted to The Division of Languages and Literature of Bard College

The evolution of head structures in diptera and the phylogeny of the order

Dipteren umfassen etwa 170 000 beschriebene Arten. Sie werden in Nematoceren („Mücken“) und Brachycera („Fliegen“) unterteilt, wobei die Nematoceren eine paraphyletische Gruppe sind. Der Schwerpunkt der vorliegenden Arbeit liegt auf den Nematoceren. Die Ziele der vorgelegten Arbeit waren die Dokumentation morphologischer Daten (1), die Zusammenstellung eines morphologischen Datensatzes (2), die phylogenetische Auswertung der Merkmale und die Entwicklung eines evolutiven Szenarios für adulte und larvale Kopfstrukturen. Hierzu wurden 28 adulte und 10 larvale Vertreter detailliert morphologisch untersucht. Die Datensätze wurden kombiniert, sowie separat, analysiert. Die Ergebnisse der kombinierten Analyse und der larvalen Kopfmerkmale stützen die Monophylie der Diptera, Brachycera und Tipuloidea. Die Analyse der adulten Kopfmerkmale unterstützt keine der allgemein anerkannten Gruppen. Die Kopfmerkmale sind größtenteils durch Homoplasien beeinflusst und dadurch ehr ungeeignet für phylogenetische Untersuchungen. Deshalb wurden die morphologischen Daten auf ein aktuelles Kladogramm (Wiegmann et al. 2011), basierend auf einem umfangreichen molekularen Datensatz, aufgetragen. Auf dieser Grundlage wurde ein evolutives Szenario für adulte und larvale Kopfstrukturen entwickelt. Der Kopf adulter Dipteren ist durch zahlreiche Reduktionen der Mundwerkzeuge charakterisiert, da Nahrungsaufnahme meist nur eine untergeordnete Rolle spielt. Nehmen die adulten Tiere Nahrung auf, dann ernähren sie sich meist von flüssigen Substanzen. Im Gegensatz dazu sind Komplexaugen und Antennen, die Sinnesorgane, welche dem Auffinden eines geeigneten Sexualpartners oder einer geeigneten Stelle zur Eiablage dienen, sehr gut entwickelt. Die beinlosen Larven oder Maden leben meist in feuchter Umgebung und haben mehrfach unabhängig voneinander aquatische Habitate besiedelt. In ihrer Ernährungsweise und der Struktur der Mundwerkzeuge unterscheiden sie sich deutlich mehr voneinander als die Adulten

Bioverträgliche Ästhetik in der Kieferorthopädie: vergleichende Studie von kieferorthopädischen Polymer–Harz–Bögen mit superelastischen NiTi–Bögen hinsichtlich ihrer Bioverträglichkeit in vitro

Die Untersuchungen dieser Studie wurden mit primären Fibroblasten und Epithelzellen durchgeführt, um dem Zielgewebe in vivo zu entsprechen. Das Ziel sollte die Beurteilung der Bioverträglichkeit von NiTi– bzw. Polymerbögen im kieferorthopädischen Einsatz sein. Die Eluierung der Proben hat gezeigt, dass eine Verweildauer für kurze Zeit in einem flüssigen Milieu wie etwa dem Speichel keine biounverträglichen Auswirkungen hat. Mit den NiTi-Proben nahm das Zellwachstum im direkten NiTi–Gewebe–Kontakt nach 48 Stunden geringfügig ab. Zudem scheint die Oberfläche nach Beanspruchung Proteine zu binden und ihre Anfangsintegrität zu verlieren. Die NiTi–Drähte besitzen zunächst eine hervorragende, inerte Oberfläche, die aber trotz offensichtlich guter Bioverträglichkeit friktionsbedingte Oberflächendefekte erwirbt. Dieser resistente, biegsame Draht hat ein geringes Gewicht und ist durch seine mechanischen Eigenschaften geeignet, den kieferorthopädischen Ansprüchen gerecht zu werden, wobei nicht beurteilt werden kann, ob eine lange Verweildauer im Mund die gute Biokompatibilität tatsächlich negativ beeinflusst. Der Polymer–Harz–Bogen zeigte eine außerordentlich gute Bioverträglichkeit, die auch langfristig erhalten zu bleiben scheint. Sein geringes Gewicht belastet die Zähne nicht und die optische Transparenz macht ihn nahezu unsichtbar und ästhetisch interessant. Im Gegensatz zum NiTi–Bogen wird eine körpereigene Verkapselung durch Kollagen unterdrückt, so dass der Draht wie körpereigen anerkannt wird. Durch die Testung zeigte sich aber, wie schnell sich die Oberfläche der Optis–Bögen veränderte. Schon die Probenherstellung machte deutlich, dass der Kunststoff Farbstoffe aufnimmt, ohne dass diese sich entfernen lassen. Viele Lebensmittel wie Rotwein oder Curry könnten der Ästhetik des Drahtes schon nach kurzer Zeit entgegenwirken. Außerdem zeigte die Verformbarkeit des Bogens schnell Grenzen, so dass es im täglichen Gebrauch zu unentdeckten Brüchen des Drahtes kommen kann. Dass der transluzente Bogen von Biomers mechanisch weniger verlässlich als ein legierter Bogen ist, wird auch in einer neueren Studie bestätigt [5]. Da der Polymermantel sehr dünn und sehr weich ist, kann die Friktion im Slot die Oberfläche schnell aufrauen oder im ungünstigsten Fall sogar zerstören. Eine defekte Oberfläche kann zu einer Reaktion mit Restmonomeren durch bestimmte Substanzen oder Mikroorganismen führen. Die sehr dünne, sehr anfällige Oberfläche impliziert, dass das Spannungsverhalten des Drahtes nur durch die Glasfasern entsteht. Die Bruchanfälligkeit führt beim Tragen zu Spannungsveränderungen und geringer Belastungsfähigkeit. Die Mundhygiene beim Einsatz der Polymerbögen ist sehr wichtig, wenn die optische Transparenz erhalten bleiben soll. Die Ästhetik dieses Bogens ermöglicht aber gerade bei älteren Patienten die Entwicklung einer positiven Einstellung zur kieferorthopädischen Rekonstruktion. Die sehr gute Biokompatibilität verbunden mit einer ausgezeichneten Ästhetik zeigte auch nach Veränderung des Kunststoffs keine Biobelastung. Dieses Ergebnis lässt den Schluss zu, dass der Einsatz von Kunststoff als kieferorthopädisches Material für die zukünftige Behandlung enorme Vorteile bietet. Allerdings ist bezüglich der Zusammensetzung des Materials noch viel wissenschaftliche Forschung nötig, um eine inerte Struktur mit stabilen Spannungsverhältnissen und chemischer Beständigkeit zu gewährleisten. Dieser Polymer–Harz–Bogen kann aber durchaus sinnvoll sein, wenn bei der Patientenauswahl sorgfältig differenziert wird. Gerade Patienten, für die die Ästhetik eine Grundvoraussetzung einer notwendigen kieferorthopädischen Behandlung ist, könnten sich mit diesem Material bei guter Beratung des Behandlers eher zu einer Therapie entschließen. Ein nicht unerhebliches Problem bleibt noch die Finanzierung häufiger Folgebögen, das nur von bestimmten Patienten akzeptiert und realisiert werden kann. Der Einsatz von Polymer–Harz–Bögen ist unter ganz bestimmten Bedingungen eine gute Alternative, um eine kieferorthopädische Behandlung durchzuführen, die mit NiTi–Drähten nicht stattgefunden hätte

Step Number and Aerobic Minute Exercise Prescription and Progression in Stroke: A Roadmap

Background: While higher therapeutic intensity improves motor recovery after stroke, translating findings from successful studies is challenging without clear exercise intensity targets. We show in the DOSE trial1 more than double the steps and aerobic minutes within a session can be achieved compared with usual care and translates to improved long-term walking outcomes. Objective: We modeled data from this successful higher intensity multi-site RCT to develop targets for prescribing and progressing exercise for varying levels of walking impairment after stroke. Methods: In twenty-five individuals in inpatient rehabilitation, twenty sessions were monitored for a total of 500 one-hour physical therapy sessions. For the 500 sessions, step number and aerobic minute progression were modeled using linear mixed effects regression. Using formulas from the linear mixed effects regression, targets were calculated. Results: The model for step number included session number and baseline walking speed, and for aerobic minutes, session number and age. For steps, there was an increase of 73 steps per session. With baseline walking speed, for every 0.1 m/s increase, a corresponding increase of 302 steps was predicted. For aerobic minutes, there was an increase of.56 minutes of aerobic activity (ie, 34 seconds) per session. For every year increase in age, a decrease of.39 minutes (ie, 23 seconds) was predicted. Conclusions: Using data associated with better walking outcomes, we provide step number and aerobic minute targets that future studies can cross-validate. As walking speed and age are collected at admission, these models allow for uptake of routine measurement of therapeutic intensity. Registration: www.clinicaltrials.gov; NCT01915368

The zoonotic potential of Clostridium difficile from small companion animals and their owners

Background: Clostridium difficile infections (CDI) in humans range from asymptomatic carriage to life-threatening intestinal disease. Findings on C. difficile in various animal species and an overlap in ribotypes (RTs) suggest potential zoonotic transmission. However, the impact of animals for human CDI remains unclear. Methods: In a large-scale survey we collected 1,447 fecal samples to determine the occurrence of C. difficile in small companion animals (dogs and cats) and their owners and to assess potential epidemiological links within the community. The Germany-wide survey was conducted from July 2012-August 2013. PCR ribotyping, Multilocus VNTR Analysis (MLVA) and PCR detection of toxin genes were used to characterize isolated C. difficile strains. A database was defined and logistic regression used to identify putative factors associated with fecal shedding of C. difficile. Results: In total, 1,418 samples met the inclusion criteria. The isolation rates for small companion animals and their owners within the community were similarly low with 3.0% (25/840) and 2.9% (17/578), respectively. PCR ribotyping revealed eight and twelve different RTs in animals and humans, respectively, whereas three RTs were isolated in both, humans and animals. RT 014/0, a well-known human hospital-associated lineage, was predominantly detected in animal samples. Moreover, the potentially highly pathogenic RTs 027 and 078 were isolated from dogs. Even though, C. difficile did not occur simultaneously in animals and humans sharing the same household. The results of the epidemiological analysis of factors associated with fecal shedding of C. difficile support the hypothesis of a zoonotic potential. Conclusions: Molecular characterization and epidemiological analysis revealed that the zoonotic risk for C. difficile associated with dogs and cats within the community is low but cannot be excluded

Differences in Peak Impact Accelerations Among Foot Strike Patterns in Recreational Runners

Introduction: Running-related injuries (RRIs) occur from a combination of training load errors and aberrant biomechanics. Impact loading, measured by peak acceleration, is an important measure of running biomechanics that is related to RRI. Foot strike patterns may moderate the magnitude of impact load in runners. The effect of foot strike pattern on peak acceleration has been measured using tibia-mounted inertial measurement units (IMUs), but not commercially available insole-embedded IMUs. The aim of this study was to compare the peak acceleration signal associated with rearfoot (RFS), midfoot (MFS), and forefoot (FFS) strike patterns when measured with an insole-embedded IMU. Materials and Methods: Healthy runners ran on a treadmill for 1 min at three different speeds with their habitual foot strike pattern. An insole-embedded IMU was placed inside standardized neutral cushioned shoes to measure the peak resultant, vertical, and anteroposterior accelerations at impact. The Foot strike pattern was determined by two experienced observers and evaluated using high-speed video. Linear effect mixed-effect models were used to quantify the relationship between foot strike pattern and peak resultant, vertical, and anteroposterior acceleration. Results: A total of 81% of the 187 participants exhibited an RFS pattern. An RFS pattern was associated with a higher peak resultant (0.29 SDs; p = 0.029) and vertical (1.19 SD; p < 0.001) acceleration when compared with an FFS running pattern, when controlling for speed and limb, respectively. However, an MFS was associated with the highest peak accelerations in the resultant direction (0.91 SD vs. FFS; p = 0.002 and 0.17 SD vs. RFS; p = 0.091). An FFS pattern was associated with the lowest peak accelerations in both the resultant and vertical directions. An RFS was also associated with a significantly greater peak acceleration in the anteroposterior direction (0.28 SD; p = 0.033) than an FFS pattern, while there was no difference between MFS and FFS patterns. Conclusion: Our findings indicate that runners should be grouped by RFS, MFS, and FFS when comparing peak acceleration, rather than the common practice of grouping MFS and FFS together as non-RFS runners. Future studies should aim to determine the risk of RRI associated with peak accelerations from an insole-embedded IMU to understand whether the small observed differences in this study are clinically meaningful

Synaptic Remodeling Depends on Signaling between Serotonin Receptors and the Extracellular Matrix

Rewiring of synaptic circuitry pertinent to memory formation has been associated with morphological changes in dendritic spines and with extracellular matrix (ECM) remodeling. Here, we mechanistically link these processes by uncovering a signaling pathway involving the serotonin 5-HT7 receptor (5-HT7R), matrix metalloproteinase 9 (MMP-9), the hyaluronan receptor CD44, and the small GTPase Cdc42. We highlight a physical interaction between 5-HT7R and CD44 (identified as an MMP-9 substrate in neurons) and find that 5-HT7R stimulation increases local MMP-9 activity, triggering dendritic spine remodeling, synaptic pruning, and impairment of long-term potentiation (LTP). The underlying molecular machinery involves 5-HT7R-mediated activation of MMP-9, which leads to CD44 cleavage followed by Cdc42 activation. One important physiological consequence of this interaction includes an increase in neuronal outgrowth and elongation of dendritic spines, which might have a positive effect on complex neuronal processes (e.g., reversal learning and neuronal regeneration)

Impact of an injury hospital admission on childhood academic performance: a Welsh population-based data linkage study

Background While injuries can impact on children’s educational achievements (with threats to their development and employment prospects), these risks are poorly quantified. This population-based longitudinal study investigated the impact of an injury-related hospital admission on Welsh children’s academic performance. Methods The Secure Anonymised Information Linkage databank, 55 587 children residing in Wales from 2006 to 2016 who had an injury hospital admission (58.2% males; 16.8% born in most deprived Wales area; 80.1% one injury hospital admission) were linked to data from the Wales Electronic Cohort for Children. The primary outcome was the Core Subject Indicator reflecting educational achievement at key stages 2 (school years 3–6), 3 (school years 7–9) and 4 (school years 10–11). Covariates in models included demographic, birth, injury and school characteristics. Results Educational achievement of children was negatively associated with: pedestrian injuries (adjusted risk ratio, (95% CIs)) (0.87, (0.83 to 0.92)), cyclist (0.96, (0.94 to 0.99)), high fall (0.96, (0.94 to 0.97)), fire/flames/smoke (0.85, (0.73 to 0.99)), cutting/piercing object (0.96, (0.93 to 0.99)), intentional self-harm (0.86, (0.82 to 0.91)), minor traumatic brain injury (0.92, (0.86 to 0.99)), contusion/open wound (0.93, (0.91 to 0.95)), fracture of vertebral column (0.78, (0.64 to 0.95)), fracture of femur (0.88, (0.84 to 0.93)), internal abdomen/pelvic haemorrhage (0.82, (0.69 to 0.97)), superficial injury (0.94, (0.92 to 0.97)), young maternal age (<18 years: 0.91, (0.88 to 0.94); 19–24 years: 0.94, (0.93 to 0.96)); area based socioeconomic status (0.98, (0.97 to 0.98)); moving to a more deprived area (0.95, (0.93 to 0.97)); requiring special educational needs (0.46, (0.44 to 0.47)). Positive associations were: being female (1.04, (1.03 to 1.06)); larger pupil school sizes and maternal age 30+ years. Conclusion This study highlights the importance on a child’s education of preventing injuries and implementing intervention programmes that support injured children. Greater attention is needed on equity-focused educational support and social policies addressing needs of children at risk of underachievement, including those from families experiencing poverty

Traditional Japanese Herbal Medicine Yokukansan Targets Distinct but Overlapping Mechanisms in Aged Mice and in the 5xFAD Mouse Model of Alzheimer’s Disease

Yokukansan (YKS) is a traditional Japanese herbal medicine that has been used in humans for the treatment of several neurological conditions, such as age-related anxiety and behavioral and psychological symptoms (BPSD) related to multiple forms of dementia, including Alzheimer’s disease (AD). However, the cellular and molecular mechanisms targeted by YKS in the brain are not completely understood. Here, we compared the efficacy of YKS in ameliorating the age- and early-onset familial AD-related behavioral and cellular defects in two groups of animals: 18- to 22-month-old C57BL6/J wild-type mice and 6- to 9-month-old 5xFAD mice, as a transgenic mouse model of this form of AD. Animals were fed food pellets that contained YKS or vehicle. After 1–2 months of YKS treatment, we evaluated the cognitive improvements in both the aged and 5xFAD transgenic mice, and their brain tissues were further investigated to assess the molecular and cellular changes that occurred following YKS intake. Our results show that both the aged and 5xFAD mice exhibited impaired behavioral performance in novel object recognition and contextual fear conditioning (CFC) tasks, which was significantly improved by YKS. Further analyses of the brain tissue from these animals indicated that in aged mice, this improvement was associated with a reduction in astrogliosis, microglia activation and downregulation of the extracellular matrix (ECM), whereas in 5xFAD mice, none of these mechanisms were evident. These results show the differential action of YKS in healthy aged and 5xFAD mice. However, both aged and 5xFAD YKS-treated mice showed increased neuroprotective signaling through protein kinase B/Akt as the common mode of action. Our data suggest that YKS may impart its beneficial effects through Akt signaling in both 5xFAD mice and aged mice, with multiple additional mechanisms potentially contributing to its beneficial effects in aged animals