Acidification and Stress Physiology in a Plethodontid Salamander, Desmognathus ochrophaeus

In western Pennsylvania, chronically and episodically acidified stream habitats are common. The mountain dusky salamander, Desmognathus ochrophaeus, is an abundant species that is associated with acidified streams. The focus of this research was to (1) examine the effects of acidified habitats on the stress hormone, corticosterone, and (2) examine the effects of corticosterone on behavior. In an acidified stream site, males had a blunted corticosterone stress response after capture and handling compared to an acid neutral site. There was a trend for elevated corticosterone to inhibit several aspects of male mating behavior, including insemination of females. These data suggest that acidification may alter normal stress physiology and thereby influence the expression of mating behavior. Ultimately, this data would help to understand how environmental degradation (specifically degradation associated with acidification) affects behaviors in free living animals via the effects on stress physiology

Konkurssin jälkeen : PK-yrittäjän selviytyminen konkurssista yrittäjän näkökulmasta

Ostin yrityksen ja aloin yrittäjäksi vuonna 2002. Yli kymmenen vuotta yritykseni menestyi, kunnes vuonna 2017 se asetettiin konkurssiin. Konkurssi lamaannutti minut ja yhtäkkiä koin olevani täysin yksin. Tahot, joista ennen olin saanut apua ja tukea eivät niitä enää antaneet. Yhteiskunta tarjoaa ilmaista apua aloittaville yrittäjille esimerkiksi Uusyrityskeskusten kautta, mutta missä ovat lopettavan yrittäjän tukipalvelut? Miettiessäni aihetta pro gradu -tutkimukseeni, tiesin heti, että halusin selvittää, kuinka muut yrittäjät olivat konkurssin kokeneet ja olisiko tarjolla ollut tukea, jota en vain ollut onnistunut löytämään. Konkursseja on tutkittu paljon sekä Suomessa että kansainvälisesti. Erityisesti kansainvälisissä tutkimuksissa aihetta on käsitelty usein liiketoiminnassa epäonnistumisen eli ”business failure” kautta. Käsitteen määritelmän mukaan se voi kuitenkin pitää sisällään paljon muutakin, kuin konkurssin, esimerkiksi epäonnistumiset, joissa yrittäjä on kärsinyt taloudellisia tappioita mutta myös epäonnistumiset, joissa yrittäjä kokee epäonnistuneensa suhteessa asettamiinsa vertailuarvoihin ja odotuksiin, vaikka yritys olisikin ollut kannattava. Tässä tutkimuksessa keskityn suomalaisten pk-yrittäjien henkilökohtaisiin kokemuksiin konkurssista, jota he eivät ole itse hakeneet. Liitän tarkasteluun myös yrittämisen toimintaympäristön, jota säätelee mm. konkurssilainsäädäntö. Se vaihtelee maittain ja vaikuttaa yleiseen suhtautumiseen konkurssia kohtaan ja samalla konkurssin kokemiseen. Siten kansainvälinen kirjallisuus ei välttämättä kuvaa suomalaista yrittäjän toimintaympäristöä. Tutkimusta varten haastattelin 5 konkurssin tehnyttä yrittäjää ja kävin läpi omia muistiinpanojani tapahtuneesta. Tulosten analysoinnissa käytin narratiivista tutkimusotetta ja käsittelin omia kokemuksiani yhtenä narratiiveista. Narratiivit analysoin teemoittelun ja jaksoittelun avulla. Sekundaarisena aineistona tutkimuksessani toimivat puhelinhaastattelut yritysneuvojien kanssa sekä kirjoitukset konkurssista omilla sosiaalisen median sivuillani. Tutkimukseni lopputuloksena on, että yrittäjät kokevat jäävänsä konkurssissa yksin ja ilman apua. Jos yhteiskunta haluaa tukea konkurssin tehneiden yrittäjien paluuta yrittäjyyteen, sen tulisi panostaa tukipalveluihin konkurssin tehneille yrittäjille, sekä tarkastella mm. konkurssilakia, jotta ao. yrittäjien mahdollisuudet jatkaa yrittämistä paranisivat. Tällä olisi vaikutusta myös yleiseen suhtautumiseen konkurssin tehneeseen yrittäjään ja siten hänen hyvinvointiinsa

Verification of the electromagnetic deep-penetration effect in the real world

The deep penetration of electromagnetic waves into lossy media can be obtained by properly generating inhomogeneous waves. In this work, for the very first time, we demonstrate the physical implementation and the practical relevance of this phenomenon. A thorough numerical investigation of the deep-penetration effects has been performed by designing and comparing three distinct practical radiators, emitting either homogeneous or inhomogeneous waves. As concerns the latter kind, a typical Menzel microstrip antenna is first used to radiate improper leaky waves. Then, a completely new approach based on an optimized 3-D horn TEM antenna applied to a lossy prism is described, which may find applications even at optical frequencies. The effectiveness of the proposed radiators is measured using different algorithms to consider distinct aspects of the propagation in lossy media. We finally demonstrate that the deep penetration is possible, by extending the ideal and theoretical evidence to practical relevance, and discuss both achievements and limits obtained through numerical simulations on the designed antennas

Chemically exfoliated graphene detects NO2 at the ppb level

Abstract The high sensitivity of graphene to the adsorption/desorption of gas molecule, is at the very beginning of its exploitation. This sensitivity relies on the two-dimensional nature of graphene allowing a total exposure of all its atoms to the adsorbing gas molecules, thus providing the greatest sensor area per unit volume. Indeed several technological limits weigh on the synthesis and manipulation of the material for the device fabrication. Herein a simple approach to fabricate conductometric sensors based on chemically exfoliated natural graphite is presented. The devices were tested upon sub-ppm concentrations of NO 2 in environmental conditions and show the ability to detect this toxic gas down to few ppb at room temperature

Angiogenesis in hand chondroma: an immunohistochemical study.

Hand chondroma is a particular cartilagineous tumour, being clinically benign, but morphologically malignant. This study investigates the expression of VEGF together with other growth factors and proliferation markers such as TGF&bT2, Ki-67, TNF, FGF1, P53 in 8 cases of hand chondroma treated with courettage, in order to define the ethiopathogenesis of this tumour and the clinical significance of the resulting immunohistochemical profile, with particular respect to angiogenesis. VEGF was expressed in all cases; 5 cases were positive for TFGβ2 and 3 for PDGF. None of the other factors was expressed. On the basis of histologic results a specific model of tumour progression based on the indicators of angiogenesis could be related to hand tumours, in which VEGF expression should be the first stadium of the tumour aggressiveness, and the following PDGF, TGF 2 expression should be accompanied with a morphological outline worsening. Nevertheless the non constant expression of these indicators and the absent expression of proliferated indicators can explain the scant tendency to the relapse in presence of accurate curettage. It is important to remember that the cellular polymorphism typical of the cartilaginous tumours does not allow the application of an only oncogenesis model

Surgical treatment of a giant tibial high-grade mixofibrosarcoma with preservation of limb function: a case report

Myxofibrosarcoma is one of the most common sarcomas in elderly patients showing a slight male prevalence. The tumor is mainly located in lower and upper extremities and rarely in trunk, neck and feet. We present a case of a 84-year-old man referred to our tumour center with a giant and neglected high-grade tibial myxofibrosarcoma in the anteromedial side of tibial mid-diaphysis. Large size lesions in association with older age may jeopardise the maintenance of limb vitality, vascularity and stability

Graphene-based Schottky Device Detecting NH3 at ppm level in Environmental Conditions

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Effect of graphene nano-platelet morphology on the elastic modulus of soft and hard biopolymers

Abstract Free-standing biocomposites were fabricated by solvent casting and hot-pressing employing two bio-polyesters having diverse elastic (Young's) moduli (soft and hard), reinforced with different graphene nanoplatelets (GnPs). Systematic mechanical measurements were conducted to investigate the effect of GnP thickness and lateral size on the elastic moduli. Comparisons were made with other reinforcing nanostructured filers such as organoclay, MoS 2 , Fe 2 O 3 , carbon black and silica nanoparticles. Upon solvent casting, GnPs did not perform better than the other model fillers in increasing the elastic modulus of the soft bio-polyester. Upon hot-pressing however, large (>300 nm) multi-layer GnPs (≥8 layers) more than doubled the elastic modulus of the soft bio-polyester matrix compared to other GnPs and fillers. This effect was attributed to the optimized alignment of the large 2D GnP flakes within the amorphous soft polymer. In contrast, hot-pressing did not yield superior elastic modulus enhancement for the hard bio-polyester when hot-pressed. GnPs only induced 30% enhancement for both processes. Moreover, multi-layer large GnPs were shown to suppress the thermally-induced stiffness reduction of the soft bio-polyester near its melting temperature. A theoretical analysis based on the spring network model is deployed to describe the impact of the GnP alignment on the elastic moduli enhancement

Optimization of multilayer graphene-based gas sensors by ultraviolet photoactivation

Nitrogen dioxide (NO2) is a potential hazard to human health at low concentrations, below one part per million (ppm). NO2 can be monitored using gas sensors based on multi-layered graphene operating at ambient temperature. However, reliable detection of concentrations on the order of parts per million and lower is hindered by partial recovery and lack of reproducibility of the sensors after exposure. We show how to overcome these longstanding problems using ultraviolet (UV) light. When exposed to NO2, the sensor response is enhanced by 290 % − 550 % under a 275 nm wavelength light emitting diode irradiation. Furthermore, the sensor’s initial state is completely restored after exposure to the target gas. UV irradiation at 68 W/m2 reduces the NO2 detection limit to 30 parts per billion (ppb) at room temperature. We investigated sensor performance optimization for UV irradiation with different power densities and target gases, such as carbon oxide and ammonia. Improved sensitivity, recovery, and reproducibility of UV-assisted graphene-based gas sensors make them suitable for widespread environmental applications

Effects of transportation, transport medium and re-housing on Xenopus laevis (Daudin)

Understanding the immediate and longer-term effects of transportation and re-housing in a laboratory species is crucial in order to refine the transfer process, enable the optimal introduction of new animals to a novel environment and to provide a sufficient acclimatisation period before usage. Whilst consideration of animal welfare in most model vertebrate species has received attention, little quantitative evidence exists for the optimal care of the common laboratory amphibian Xenopus laevis. Techniques for the non-invasive welfare assessment of amphibians are also limited and here a non-invasive physiological assay was developed to investigate the impacts of transportation, transport medium and re-housing on X. laevis. First the impacts of transportation and transport medium (water, damp sponge or damp sphagnum moss) were investigated. Transportation caused an increase in waterborne corticosterone regardless of transport medium. Frogs transported in damp sphagnum moss also had a greater decrease in body mass in comparison to frogs not transported, suggesting that this is the least suitable transport medium for X. laevis. Next the prolonged impacts of transportation and re-housing were investigated. Frogs were transported between research facilities with different housing protocols. Samples were collected prior to and immediately following transportation, as well as 1 day, 7 days and 35 days after re-housing. Water-borne corticosterone increased following transportation and remained high for at least 7 days, decreasing to baseline levels by 35 days. Body mass decreased following transportation and remained lower than baseline levels across the entire 35 day observation period. These findings suggest the process of transportation and re-housing is stressful in this species. Together these findings have important relevance for both improving animal welfare and ensuring optimal and efficient scientific research