Preliminary Assessment of Climatic Sensitivity of Riparian Old-Growth Eastern Hemlock

Eastern hemlock is a long-lived, slow growing climax species in North America currently undergoing a major decline in population due to a combination of effects derived from hemlock woolly adelgid (HWA) as well as changing climate patterns. Data was collected in an old-growth, riparian hemlock forest within the West Virginia University Research Forest to understand the effect of monthly climate factors (mean temperature, mean precipitation, and climate moisture index (CMI)) on hemlock radial growth. Results indicated that March mean temperature and May CMI of the current growth year are positively associated with hemlock growth whereas prior year summer conditions of each climate variable resulted in negative correlations. Spring temperature as well as winter precipitation of the current year also lessened hemlock growth. Many of the significant relationships ascertained by this study were well supported by other studies; however, increased June precipitation and CMI resulting in a reduction in growth may be explained by summer storm damage or root anoxia, resulting in lessened growth1,2. Also, previous studies conducted south of the study area found winter precipitation to positively affect growth; this incongruence is explainable by differences in precipitation types and how heavy snow could contribute to hemlock damage2. Through the establishment of these relationships, it may be better understood how riparian, old-growth hemlock stands within central Appalachia will respond to changing monthly climate patterns

Diazonium-based anchoring of PEDOT on Pt/Ir electrodes via diazonium chemistry

Conducting polymers, specifically poly (3,4-ethylenedioxythiophene) (PEDOT), have recently been coated onto Pt/Ir electrodes intended for neural applications, such as deep brain stimulation (DBS). This modification reduces impedance, increases biocompatibility, and increases electrochemically active surface area. However, direct electropolymerization of PEDOT onto a metallic surface results in physically adsorbed films that suffer from poor adhesion, precluding their use in applications requiring in vivo functionality (i.e. DBS treatment). In this work, we propose a new attachment strategy, whereby PEDOT is covalently attached to an electrode surface through an intermediate phenylthiophene layer, deposited by electrochemical reduction of a diazonium salt. Our electrodes retain their electrochemical performance after more than 1000 redox cycles, whereas physically adsorbed films begin to delaminate after only 40 cycles. Additionally, covalently attached PEDOT maintained strong adhesion even after 10 minutes of ultrasonication (vs. 10 s for physically adsorbed films), confirming its suitability for long-term implantation in the brain. The simple two-step covalent attachment strategy proposed here is particularly useful for neural applications and could also be adapted to introduce other functionalities on the conducting surface

Ciliary Beating Recovery in Deficient Human Airway Epithelial Cells after Lentivirus Ex Vivo Gene Therapy

Primary Ciliary Dyskinesia is a heterogeneous genetic disease that is characterized by cilia dysfunction of the epithelial cells lining the respiratory tracts, resulting in recurrent respiratory tract infections. Despite lifelong physiological therapy and antibiotics, the lungs of affected patients are progressively destroyed, leading to respiratory insufficiency. Recessive mutations in Dynein Axonemal Intermediate chain type 1 (DNAI1) gene have been described in 10% of cases of Primary Ciliary Dyskinesia. Our goal was to restore normal ciliary beating in DNAI1–deficient human airway epithelial cells. A lentiviral vector based on Simian Immunodeficiency Virus pseudotyped with Vesicular Stomatitis Virus Glycoprotein was used to transduce cultured human airway epithelial cells with a cDNA of DNAI1 driven by the Elongation Factor 1 promoter. Transcription and translation of the transduced gene were tested by RT–PCR and western blot, respectively. Human airway epithelial cells that were DNAI1–deficient due to compound heterozygous mutations, and consequently had immotile cilia and no outer dynein arm, were transduced by the lentivirus. Cilia beating was recorded and electron microscopy of the cilia was performed. Transcription and translation of the transduced DNAI1 gene were detected in human cells treated with the lentivirus. In addition, immotile cilia recovered a normal beat and outer dynein arms reappeared. We demonstrated that it is possible to obtain a normalization of ciliary beat frequency of deficient human airway epithelial cells by using a lentivirus to transduce cells with the therapeutic gene. This preliminary step constitutes a conceptual proof that is indispensable in the perspective of Primary Ciliary Dyskinesia's in vivo gene therapy. This is the first time that recovery of cilia beating is demonstrated in this disease

Climate change and oak growth decline: Dendroecology and stand productivity of a Turkey oak (Quercus cerris L.) old stored coppice in Central Italy

• We combined stem volume increment analysis with dendroecological tools to address two unresolved issues concerning oak dieback in Mediterranean areas: early detection of changes in stand growth, and identification of mechanisms for observed growth declines. • We reconstructed productivity of a stored coppice formed by Turkey oak (Quercus cerris) to test if its growth decline was linked to climatic variability, while also accounting for age-related and sociological factors. • Drought in May–June and in prior-year late summer-autumn was negatively correlated with current growth during 1974–2006. Previous November water balance was the strongest signal. Moving Correlation Functions (11 y windows) indicated that the May–June signal remained dominant until 1996, thereafter falling to non-significant values in parallel with the May–June water balance drying trend; at the same time the previous autumn correlations reached significant values. Since 1994 there was a two-year lagged response to June water balance, suggesting that, when growth declined, loss of current-year climate signals was accompanied by the emergence of previous-year ones. • Growth and productivity of deciduous oaks in Mediterranean environments is linked to late spring-early summer hydrologic balance; at both annual and decadal timescales, oak growth decline was associated with a delayed response to climate

Intestinal parasitic infections in HIV-infected patients, Lao People's Democratic Republic

HIV infection is an emerging problem in Laos. We conducted the first prospective study on intestinal parasites, including opportunistic protozoa, in newly diagnosed HIV infected patients, with or without diarrhea. The aims were to describe the spectrum of infections, to determine their prevalence and to assess their associations with diarrhea, CD4 cell count, place of residence and living conditions.; One to three stool samples over consecutive days were obtained from 137 patients. The Kato thick smear method, formalin-ethyl concentration and specific stains for coccidia and microsporidia diagnosis were performed on 260 stool samples. Baseline characteristics regarding relevant demographics, place of residence and living conditions, clinical features including diarrhea, were collected using a standardized questionnaire.; The 137 patients were young (median age: 36 years) and severely immunocompromised (83.9% at WHO stage 3 or 4, median CD4 cell count: 41/mm3). Diarrhea was present in 43.0% of patients. Parasite infection was found in 78.8% of patients, infection with at least two species in 49.6%. Prevalence rates of protozoan and helminth infections were similar (54.7% and 58.4% respectively). Blastocystis sp. was the most frequent protozoa (26.3%). Cryptosporidium sp., Cytoisospora belli and microsporidia, found at low prevalence rates (6.6%, 4.4%, 2.9%, respectively), were described for the first time in Laos. Cryptosporidium sp. was associated with persistent diarrhea. Strongyloides stercoralis was the most prevalent helminth following Opisthorchis viverrini (20.4% and 47.5% respectively). The most immunocompromised patients, as assessed by a CD4 count ≤ 50 cells/mm3, were more likely to be infected with intestinal parasites.; HIV infection was mainly diagnosed at an advanced stage of immunosuppression in Lao patients. Intestinal parasite infections were highly prevalent regardless of their diarrheal status. Opportunistic infections were reported. Improving the laboratory diagnosis of intestinal parasite infections and the knowledge on their local risk factors is warranted

Thinning increases climatic resilience of red pine

Forest management techniques such as intermediate stand-tending practices (e.g., thinning) can promote climatic resiliency in forest stands by moderating tree competition. Residual trees gain increased access to environmental resources (i.e., soil moisture, light), which in turn has the potential to buffer trees from stressful climatic conditions. The influences of climate (temperature and precipitation) and forest management (thinning method and intensity) on the productivity of red pine (Pinus resinosa Ait.) in Michigan were examined to assess whether repeated thinning treatments were able to increase climatic resiliency (i.e., maintaining productivity and reduced sensitivity to climatic stress). The cumulative productivity of each thinning treatment was determined, and it was found that thinning from below to a residual basal area of 14 m2·ha−1 produced the largest average tree size but also the second lowest overall biomass per acre. On the other hand, the uncut control and the thinning from above to a residual basal area of 28 m2·ha−1 produced the smallest average tree size but also the greatest overall biomass per acre. Dendrochronological methods were used to quantify sensitivity of annual radial growth to monthly and seasonal climatic factors for each thinning treatment type. Climatic sensitivity was influenced by thinning method (i.e., thinning from below decreased sensitivity to climatic stress more than thinning from above) and by thinning intensity (i.e., more intense thinning led to a lower climatic sensitivity). Overall, thinning from below to a residual basal area of 21 m2·ha−1 represented a potentially beneficial compromise to maximize tree size, biomass per acre, and reduced sensitivity to climatic stress, and, thus, the highest level of climatic resilience. </jats:p

Conducting Polymers Doped with Bifunctional Copolymers for Improved Organic Batteries

We propose a simple yet very versatile method to functionalize conducting polymers by the use of a bifunctional copolymer that can act as a redox-active dopant. A copolymer composed of 4-vinylcatechol and styrenesulfonic acid moieties was used as both the source of ions and the dopant for poly­(3,4-ethylene­dioxythiophene) (PEDOT) electropolymerization. The composite polymer shows an improvement in capacity which originates from the catechol faradaic reaction (52 mAh g–1 vs 18 mAh g–1) compared to PEDOT:poly­(styrene­sulfonate) (PSS). The active material utilization in the composite polymer was further investigated by using HClO4 as a secondary dopant and by increasing the ratio of neutral 4-vinylcatechol in the bifunctional copolymer to obtain a higher energy density electrode. Characterization by X-ray diffraction and atomic force microscopy hints at phase separation between PEDOT and the doping copolymer. Consequently, 4-vinylcatechol electronic connection to PEDOT is weakened at the microscale which prevents its complete utilization. These findings show the complex interaction between a conducting polymer and its dopant. The possibility to further tune the bifunctional copolymer composition, structure, and polymerization strategy should lead to improved energy storage performances and other new functional materials that explore properties imbedded in molecular units