An Investigation on the antimicrobial activity of some endemic plant species from Turkey

In this study performed on six endemic plant species, antimicrobial activity was observed in Campanula lyrata subsp.lyrata and Abies nordmanniana subsp. bornmuelleriana plants. The minimum inhibitoryconcentration of C. lyrata subsp. lyrata (leaf and flower) extract was found to be 29 mg/ml for Baccillus subtilis and 14.5 mg/ml for Staphylococcus aureus, and the minimum inhibitory concentration (MIC) of Abies nordmanniana subsp. bornmuelleriana (leaf) extract was found to be > 314 mg/ml for B. subtilis and when minimum bacteriocidal concentration (MBC) results were evaluated, it was observed that the plant extracts had bacteriocidal effects. No antimicrobial activity was observed inthe other plant extracts, namely, Onosma bornmuelleri (leaf- flower), Dianthus balansae (leaf- flower), Alyssum pateri subsp. pateri (seed) and Scabiosa columbaria subsp. paphlagonica (leaf) extracts thatwere tested

A new stakeholder opinion-based rapid sustainability assessment method (RSAM) for existing residential buildings

In many developing countries, several strategies and programs have been established to support the green building initiative, but overall progress is too slow to keep up with the global advances. To accelerate progress in building sustainability as well as to aid the decision-making process of different parties involved, a tailored quantification method for the sustainability performance of buildings is needed. The study presents a Rapid Sustainability Assessment Method (RSAM) – a fast and easy-to-implement system developed using indicators and their respective weights obtained from stakeholders and an assessment approach based on residents’ responses. It was then applied to measure the sustainability performance of several residential buildings (from eras: before 1991, from 1991 to 1998, and after 1998) in the capital of Kazakhstan, Nur-Sultan (formerly Astana). Results differentiated well between the buildings of different era, revealing that even new buildings certified via international green building rating systems do not entirely satisfy the vision of sustainability of the capital’s residents. Although the residents’ opinion-based method was developed for existing residential buildings, it is flexible enough to accommodate future changes e.g. including data obtained from other stakeholders (e.g. building management) and assessing non-residential buildings. RSAM is further applicable to residential buildings constructed after 1950s in other similar regions including post-Soviet and Eastern Bloc countries

From Selection to Instruction and Back: Competing Conformational Selection and Induced Fit Pathways in Abiotic Hosts

Two limiting cases of molecular recognition, induced fit (IF) and conformational selection (CS), play a central role in allosteric regulation of natural systems. The IF paradigm states that a substrate “instructs” the host to change its shape after complexation, while CS asserts that a guest “selects” the optimal fit from an ensemble of preexisting host conformations. With no studies that quantitatively address the interplay of two limiting pathways in abiotic systems, we herein and for the first time describe the way by which twisted capsule M-1, encompassing two conformers M-1(+) and M-1(−), trap CX4 (X=Cl, Br) to give CX4⊂M-1(+) and CX4⊂M-1(−), with all four states being in thermal equilibrium. With the assistance of 2D EXSY, we found that CBr4 would, at its lower concentrations, bind M-1 via a M-1(+)→M-1(−)→CBr4⊂M-1(−) pathway corresponding to conformational selection. For M-1 complexing CCl4 though, data from 2D EXSY measurements and 1D NMR line-shape analysis suggested that lower CCl4 concentrations would favor CS while the IF pathway prevailed at higher proportions of the guest. Since CS and IF are not mutually exclusive, we reason that our work sets the stage for characterizing the dynamics of a wide range of already existing hosts to broaden our fundamental understanding of their action. The objective is to master the way in which encapsulation takes place for designing novel and allosteric sequestering agents, catalysts and chemosensors akin to those found in nature

Melatonin Delays Brain Aging by Decreasing the Nitric Oxide Level

Aging is believed to be a first-order risk factor for most neurodegenerative disorders. The neuronal cell loss that occurs with aging has been partly attributed to increased production of nitric oxide and high caspase activity. Melatonin (MLT) might have a role in the regulation of nitric oxide in the brain. We investigated the effects of MLT on the nitrite/nitrate levels and caspase-3 enzyme activity in the frontal cortex, temporal cortex, and hippocampus of young and aged rats. There was no significant difference between the nitrite levels in the frontal cortex and hippocampus of young and aged animals. In the temporal cortex of aged rats, the nitrite level, however, was significantly higher (P < 0.001). In the aged group, MLT significantly decreased these levels in the brain regions. Caspase-3 enzyme activity in the temporal and frontal cortices was significantly higher in aged rats when compared to the control group (P < 0.05). Melatonin did not cause significant changes in caspase-3 activity in any brain region of both young and aged rats. Thus, brain regions demonstrate different caspase-3 enzyme activities and nitrite levels in the aging process. Exogenous MLT administration might delay brain aging (by moderation of death of neurons and glia) via decreasing the nitrite level.В аспекті розвитку нейродегенеративних розладів старіння розглядається як фактор ризику першого порядку. Втрату нервових клітин, яка відбувається з віком, пов’язували, в усякому разі частково, зі збільшенням продукції оксиду азоту та високій активності каспаз. Мелатонін (МТ) може відігравати певну роль у регуляції рівня оксиду азоту в мозку. Ми досліджували впливи МТ на рівні нітритів/нитратів та ензиматичну активність каспази-3 у фронтальній і темпоральній корі та гіпокампі молодих і старих щурів. Істотних відмінностей між рівнями нітритів у фронтальній корі та гіпокампі молодих і старих тварин виявлено не було, проте цей рівень в темпоральній корі старих тварин був істотно вищим (P < 0.001). У групі старих щурів МТ істотно знижував рівні нітритів в структурах мозку. Активність каспази-3 у фронтальних і темпоральних зонах кори старих щурів була достовірно вище, ніж у контрольних тварин (P < 0.05). Мелатонін не викликав істотних змін активності каспази-3 у всіх досліджених структурах мозку як молодих, так і старих щурів. Отже, рівні активності каспази-3 та концентрації нітритів в різних структурах мозку в перебігу процесу старіння демонструють певну специфічність. Вплив екзогенного МТ, мабуть, затримує старіння мозку (зменшуючи інтенсивність загибелі нейронів і глії) за рахунок зниження рівнів нітрит

The Thermal Behaviour of Three Different Auger Pressure Grouted Piles Used as Heat Exchangers

Three auger pressure grouted (APG) test piles were constructed at a site in Richmond, Texas. The piles were each equipped with two U-loops of heat transfer pipes so that they could function as pile heat exchangers. The piles were of two different diameters and used two different grouts, a standard APG grout and a thermally enhanced grout. Thermal response tests, where fluid heated at a constant rate is circulated through the pipe loops, were carried out on the three piles, utilising either single or double loops. The resulting test data can be used to determine the surrounding soil thermal conductivity and the pile thermal resistance, both essential design parameters for ground source heat pump systems using pile heat exchangers. This paper uses parameter estimation techniques to fit empirical temperature response curves to the thermal response test data and compares the results with standard line source interpretation techniques. As expected, the thermal response tests with double loops result in smaller thermal resistances than the same pile when the test was run with a single loop. Back analysis of the pile thermal resistance also allows calculation of the grout thermal properties. The thermally enhanced grout is shown to have inferior thermal properties than the standard APG grout. Together these analyses demonstrate the importance of pile size, grout thermal properties and pipe positions in controlling the thermal behaviour of heat exchanger piles

Is complexity leadership theory complex enough? A critical appraisal, some modifications and suggestions for further research

Scholars are increasingly seeking to develop theories that explain the underlying processes whereby leadership is enacted. This shifts attention away from the actions of ‘heroic’ individuals and towards the social contexts in which people with greater or lesser power influence each other. A number of researchers have embraced complexity theory, with its emphasis on non-linearity and unpredictability. However, some complexity scholars still depict the theory and practice of leadership in relatively non-complex terms. They continue to assume that leaders can exercise rational, extensive and purposeful influence on other actors to a greater extent than is possible. In effect, they offer a theory of complex organizations led by non-complex leaders who establish themselves by relatively non-complex means. This testifies to the enduring power of ‘heroic’ images of leader agency. Without greater care, the terminology offered by complexity leadership theory could become little more than a new mask for old theories that legitimize imbalanced power relationships in the workplace. This paper explores how these problems are evident in complexity leadership theory, suggests that communication and process perspectives help to overcome them, and outlines an agenda for further research on these issues

Past Achievements and Future Challenges in 3D Photonic Metamaterials

Photonic metamaterials are man-made structures composed of tailored micro- or nanostructured metallo-dielectric sub-wavelength building blocks that are densely packed into an effective material. This deceptively simple, yet powerful, truly revolutionary concept allows for achieving novel, unusual, and sometimes even unheard-of optical properties, such as magnetism at optical frequencies, negative refractive indices, large positive refractive indices, zero reflection via impedance matching, perfect absorption, giant circular dichroism, or enhanced nonlinear optical properties. Possible applications of metamaterials comprise ultrahigh-resolution imaging systems, compact polarization optics, and cloaking devices. This review describes the experimental progress recently made fabricating three-dimensional metamaterial structures and discusses some remaining future challenges

Comparison of Three Targeted Enrichment Strategies on the SOLiD Sequencing Platform

Despite the ever-increasing throughput and steadily decreasing cost of next generation sequencing (NGS), whole genome sequencing of humans is still not a viable option for the majority of genetics laboratories. This is particularly true in the case of complex disease studies, where large sample sets are often required to achieve adequate statistical power. To fully leverage the potential of NGS technology on large sample sets, several methods have been developed to selectively enrich for regions of interest. Enrichment reduces both monetary and computational costs compared to whole genome sequencing, while allowing researchers to take advantage of NGS throughput. Several targeted enrichment approaches are currently available, including molecular inversion probe ligation sequencing (MIPS), oligonucleotide hybridization based approaches, and PCR-based strategies. To assess how these methods performed when used in conjunction with the ABI SOLID3+, we investigated three enrichment techniques: Nimblegen oligonucleotide hybridization array-based capture; Agilent SureSelect oligonucleotide hybridization solution-based capture; and Raindance Technologies' multiplexed PCR-based approach. Target regions were selected from exons and evolutionarily conserved areas throughout the human genome. Probe and primer pair design was carried out for all three methods using their respective informatics pipelines. In all, approximately 0.8 Mb of target space was identical for all 3 methods. SOLiD sequencing results were analyzed for several metrics, including consistency of coverage depth across samples, on-target versus off-target efficiency, allelic bias, and genotype concordance with array-based genotyping data. Agilent SureSelect exhibited superior on-target efficiency and correlation of read depths across samples. Nimblegen performance was similar at read depths at 20× and below. Both Raindance and Nimblegen SeqCap exhibited tighter distributions of read depth around the mean, but both suffered from lower on-target efficiency in our experiments. Raindance demonstrated the highest versatility in assay design

Protein binding hot spots and the residue-residue pairing preference: a water exclusion perspective

<p>Abstract</p> <p>Background</p> <p>A protein binding hot spot is a small cluster of residues tightly packed at the center of the interface between two interacting proteins. Though a hot spot constitutes a small fraction of the interface, it is vital to the stability of protein complexes. Recently, there are a series of hypotheses proposed to characterize binding hot spots, including the pioneering O-ring theory, the insightful 'coupling' and 'hot region' principle, and our 'double water exclusion' (DWE) hypothesis. As the perspective changes from the O-ring theory to the DWE hypothesis, we examine the physicochemical properties of the binding hot spots under the new hypothesis and compare with those under the O-ring theory.</p> <p>Results</p> <p>The requirements for a cluster of residues to form a hot spot under the DWE hypothesis can be mathematically satisfied by a biclique subgraph if a vertex is used to represent a residue, an edge to indicate a close distance between two residues, and a bipartite graph to represent a pair of interacting proteins. We term these hot spots as DWE bicliques. We identified DWE bicliques from crystal packing contacts, obligate and non-obligate interactions. Our comparative study revealed that there are abundant <it>unique </it>bicliques to the biological interactions, indicating specific biological binding behaviors in contrast to crystal packing. The two sub-types of biological interactions also have their own signature bicliques. In our analysis on residue compositions and residue pairing preferences in DWE bicliques, the focus was on interaction-preferred residues (ipRs) and interaction-preferred residue pairs (ipRPs). It is observed that hydrophobic residues are heavily involved in the ipRs and ipRPs of the obligate interactions; and that aromatic residues are in favor in the ipRs and ipRPs of the biological interactions, especially in those of the non-obligate interactions. In contrast, the ipRs and ipRPs in crystal packing are dominated by hydrophilic residues, and most of the anti-ipRs of crystal packing are the ipRs of the obligate or non-obligate interactions.</p> <p>Conclusions</p> <p>These ipRs and ipRPs in our DWE bicliques describe a diverse binding features among the three types of interactions. They also highlight the specific binding behaviors of the biological interactions, sharply differing from the artifact interfaces in the crystal packing. It can be noted that DWE bicliques, especially the unique bicliques, can capture deep insights into the binding characteristics of protein interfaces.</p