bluuebunny/crossref_metadata_2025 huggingface dataset:
FAKTOR-FAKTOR YANG MEMPENGARUHI KEUNGGULAN BERSAING PADA USAHA TRAVEL (Studi pada Usaha Travel Sederhana Tranz di Bandar Lampung)
Authors: Prikurnia Anas Khair , Sormin Rahma Diani , Kurniawan Rudi
Published: July 2024

Tujuan Penelitian ini adalah untuk mengetahui pengaruh kualitas produk dan kualitas pelayanan terhadap keunggulan bersaing Sederhana Trans di Bandarlampung. Tempat penelitian ini di lakukan di Jalan Mayor Salim Batubara Teluk Betung Bandarlampung yang merupakan kantor usaha travel Sederhana trans. Sampel dalam penelitian ini dipilih menggunakan purposive sampling dan terdiri dari konsumen yang sudah pernah menggunakan jasa travel Sederhana Trans. Analisis data penelitian ini menggunakan teknik regresi dengan alat uji SPSS 16. Hasil dari penelitian ini menunjukkan bahwa keunggulan bersaing (variabel Y) pada perusahaan travel Sederhana Trans dipengaruhi oleh faktor kualitas produk (variabel X1) dan kualitas pelayanan (variabel X2). Hasil uji F menunjukkan secara simultan kualitas produk dan kualitas pelayanan memiliki pengaruh yang positif dan signifikan terhadap keunggulan bersaing.
STRATEGI BERSAING AYAM GORENG MASTER CHICKEN BANDAR LAMPUNG (Studi Kasus Pada Ayam Goreng Master Chicken Bandar Lampung)
Authors: Kurniawan Rudi , Prikurnia Anas Khair , Nurbaiti Seni
Published: July 2024

ABSTRAKLampung merupakan daereh sedang berkembang dimana fasilitas-fasilitas seperti tempat penginapan di kota Bandar Lampung saat ini terus diciptakan, selain Fasilitas-fasilitas lain mengikuti perkembangan rumah makan baik berskala besar maupun kecil. Rumah Makan di Bandar Lampung dari waktu ke waktu menunjukan perkembangan yang signifikan. Hal ini terlihat dari banyaknya usaha rumah makan yang di bangun tersebar hampir seluruh wilayah Bandar Lampung. Penelitian ini digunakan metode analisis Matrik Daya Tarik Industri atau yang sering disingkat MDTI.yaitu menentukan variable-variabel yang berpengaruh bagi perusahaan.variable eksternal dan internal. Setelah itu pendekatan kuantitatif dengan pemberian bobot pada variable eksternal dan internal perusahaan maupun konsumen. pemberian bobot, total keseluruhan variable eksternal maupun internal yaitu 1 atau 100%. dalam pemberian nilai, digunakan criteria tertentu yaitu menggunakan skala 4. Dari analisis variabel internal, diketahui adanya peluang perusahaan yang ditunjukkan oleh indikator: variasi produk pelayanan dari segi kecepatan dan keterampilan dan fasilitas dari segi toilet dan fasilitas pendukung lainnya hasil analisis variabel eksternal, diketahui bahwa peluang bagi perusahaan yang ditunjukkan oleh indikator: daya beli konsumen strategi berdasarkan MDTI, yaitu dengan: Pertumbuhan Selektif, Investasi Agresif, dan Memelihara Posisi Di Tempat Lainmemberikan nilai tambah bagi konsumen lokasi perusahaan, disarankan agar melakukan desentralisasi lokasi sehingga mudah dijangkau konsumen dan sumber daya manusia, menambah jumlah karyawan konsumen karyawan terpenuhi.Indikator ancaman bagi perusahaan jaminan produk, maka disarankan perusahaan melakukan kerja sama dengan departemen kesehatan dan Badan POM untuk melakukan pencegahan dan penanggulangan virus flu burung, dan memberikan dipenelitian lokasi strategis guna menarik pelanggan potensial.Kata   Kunci:   Startegi,   Persaingan,   dan  MDTI
ANALISIS STRATEGI UMKM ANGKRINGAN BANG JALI DALAM MENINGKATKAN KEUNGGULAN BERSAING
Authors: Fajri Ratu Chaterine , Prikurnia Anas Khair
Published: July 2024

Angkringan ialah tempat makan dengn harga yang cukup murah serta Identik dengan kebersamaan serta kesederhanaan nya buat sekedar makan, minum kopi, serta nongkrong. Angkringan telah banyak ditemukan di Kota Bandar Lampung. Angkringan sebagai bentuk perekonomian kecil yang bisa bertahan dan bersaing dengan Rumah Makan cepat saji juga warung-warung lain di Kota Bandar Lampung. Salah satu angkringan yang berada di Kota Bandar Lampung ialah Angkringan Bang Jali yang berada di Jl. Jenderal Sudirman 66-62, namun Angkringan – angkringan serupa yang berada di dekat Angkringan Bang Jali pun semakin bersaing dalam merebut pelanggan terdapat beberapa Angkringan yang lain dan Warung Ketoprak Romo. Banyak menu makanan dan minuman yang tersedia di Angkringan Bang jali dan memiliki ciri khas menu yaitu Nasi Goreng Rempah Krakatau yang sangat diminati bagi para pelanggan angkringan tersebut. Angkringan Bang Jali ini berada diluar ruangan jadi ketika hujan datang itu akan membuat para pelanggan kurang menikmati, disaat weekend angkringan ini ramai di datangi para pelanggan namun disaat weekday angkringan ini kurang ramai di datangi pelanggan. Strategi manajemen pemasaran untuk mengatasi perubahan lingkungan eksternal juga internal dapat dilihat dengan kekuatan, kelemahan, ancaman dan peluang. Analisis SWOT merupakan cara yang tepat untuk mengatasi permasalahan dalam manajemen pemasaran tersebut.Kata Kunci : Angkringan, Strategi, Pemasaran.
PENGARUH KUALITAS PELAYANAN DAN FASILITAS TERHADAP KEPUASAN KONSUMEN STUDI PADA MIE AYAM MBOK_DEE DI BANDAR LAMPUNG
Authors: Angga aji saputra Saputra Aji , Aginda danuarta Aginda , Alfina amalia Alfina , Sanjaya Vicky f
Published: July 2024

Penelitian ini bertujuan untuk mengetahui pengaruh kualitas pelayaanan dan fasilitas terhadap kepuasan konsumen pada mie ayam mbok dee di bandar lampung.metode penlitian ini adalah deskriptif dan penelitian kompratif. Populasi pada penelitian ini adalah konsumen yang melakukan pembelian pada mie ayam mbok dee di bandar lampung dan sampel penelitian ini sebanyak 80 responden, teknik pengambilan sampel dalam penelitian ini yaitu metode Accidental Peneliti berharap kepada mie ayam mbok_dee agar lebih memperhatikan kualitas pelayanannya dan juga dapat memperhatikan fasilitasnya maka konsumen mempunyai rasa ingin membeli ulang karena konsumen juga melihat dari segi pelayanan dan juga fasilitas bukan hanya tentang rasa untuk melakukan pembelian ulang
Green Chemistry Strategies for Mitigating Microplastic Pollution in Aquatic Environments
Authors: Samuel Humphrey , Makong Francis-Dominic , Ori Merit
Published: July 2024

Microplastic pollution poses a growing threat to aquatic ecosystems. This review explores green chemistry strategies for mitigating this issue. The focus is on preventing microplastic generation at the source. Strategies include designing plastic products for reusability and recyclability, developing biodegradable plastics, and utilizing alternative materials. Improved wastewater treatment processes to capture microplastics before they enter aquatic environments are addressed. Biodegradable plastics and microplastic capture methods in wastewater treatment facilities are highlighted as promising green solutions.  Green chemistry principles are emphasized throughout, highlighting the importance of environmentally friendly solutions. By implementing these strategies, we can significantly reduce microplastic pollution and protect our precious water resources.
Optimalisasi Perawatan Injektor terhadap Performa Mesin Induk di Kapal MV. Kali Mas
Authors: Hamdani Eryck , Syamsir Syamsir , Seno Abdi
Published: July 2024

Injektor ini sangat penting karena dari injektor pembakaran pada ruang bakar terjadi melalui pengabutan yang dilakukan oleh injektor, sehingga mesin induk dapat beroperasi dengan normal. Namun yang sering terjadi injektor tidak mendapatkan perawatan secara optimal sehingga sangat berpengaruh pada kelancaran performa mesin induk di Kapal MV. Kali Mas. Data yang diperoleh adalah data yang dikumpulkan dari hasil observasi dimana peneliti mengamati langsung objek penelitian, dokumentasi dimana peneliti mengambil gambar sebagai bukti, dan wawancara dimana peneliti mengajukan pertanyaan langsung kepada responden. Cara merawat injektor agar tidak terjadi penyumbatan yaitu, membersihkan lubang-lubang nozzle, dan melakukan pressure test injektor. Faktor yang dapat menyebabkan kurang optimalnya perawatan injektor yaitu, menggunakan injektor hingga melebihi jam kerja, dan perawatan yang tidak sesuai dengan PMS. Upaya pengoptimalan cara kerja injektor untuk performa mesin induk yaitu, memastikan pressure injektor saat test mencapai kebutuhan pemakaian mesin, dan mengganti nozzle jika ada spare part di workshop.
Analisis Penyebab Jangkar Larat di KM.
Authors: Rafiudin Nadha , Siska Syafni Yelvi , Yanti Melda
Published: July 2024

Kegiatan berlabuh jangkar para awak harus tetap dalam kondisi siap siaga. Agar tidak terjadi lagi kecelakaan seperti jangkar larat tersebut dan juga untuk mengetahui apa saja penyebab dari jangkar larat saat berlabuh Pada tanggal 18 November 2022 saat KM. Kendhaga Nusantara 04 sedang berlabuh jangkar di anchorage area Makassar, kapal mengalami jangkar larat yang mengakibatkan kapal hampir kandas menabrak break water. Tujuan dari penelitian ini adalah untuk mengetahui faktor-faktor yang menyebabkan terjadinya jangkar larat pada KM. Kendhaga Nusantara 04 sehingga kegiatan berlabuh jangkar dapat dilaksanakan dengan baik. Penelitian ini menggunakan metode penelitian kualitatif. Proses dan prespektif subyek lebih ditonjolkan dalam penelitian ini. Hasil penilitian menunjukan bahwa faktor yang menyebabkan jangkar larat di KM. Kendhaga Nusantara 04 adalah kurangnya kesadaran crew terhadap pentingnya proses berlabuh jangkar, pemilihan tempat berlabuh yang kurang tepat dan juga pelaksanaan proses berlabuh jangkar yang kurang tepat sesuai prosedur, kurangnya pengecekan serta perawatan terhadap peralatan berlabuh seperti jangkar, rantai jangkar, dan juga windlass.
Alzheimer’s disease linked Aβ42 exerts product feedback inhibition on γ-secretase impairing downstream cell signaling
Authors: Zoltowska Katarzyna Marta , Das Utpal , Lismont Sam , Enzlein Thomas , Maesako Masato , Houser Mei CQ , Franco Maria Luisa , Özcan Burcu , Gomes Moreira Diana , Karachentsev Dmitry , Becker Ann , Hopf Carsten , Vilar Marçal , Berezovska Oksana , Mobley William , Chávez-Gutiérrez Lucía
Published: July 2024

Amyloid β (Aβ) peptides accumulating in the brain are proposed to trigger Alzheimer’s disease (AD). However, molecular cascades underlying their toxicity are poorly defined. Here, we explored a novel hypothesis for Aβ42 toxicity that arises from its proven affinity for γ-secretases. We hypothesized that the reported increases in Aβ42, particularly in the endolysosomal compartment, promote the establishment of a product feedback inhibitory mechanism on γ-secretases, and thereby impair downstream signaling events. We conducted kinetic analyses of γ-secretase activity in cell-free systems in the presence of Aβ, as well as cell-based and ex vivo assays in neuronal cell lines, neurons, and brain synaptosomes to assess the impact of Aβ on γ-secretases. We show that human Aβ42 peptides, but neither murine Aβ42 nor human Aβ17–42 (p3), inhibit γ-secretases and trigger accumulation of unprocessed substrates in neurons, including C-terminal fragments (CTFs) of APP, p75, and pan-cadherin. Moreover, Aβ42 treatment dysregulated cellular homeostasis, as shown by the induction of p75-dependent neuronal death in two distinct cellular systems. Our findings raise the possibility that pathological elevations in Aβ42 contribute to cellular toxicity via the γ-secretase inhibition, and provide a novel conceptual framework to address Aβ toxicity in the context of γ-secretase-dependent homeostatic signaling.
Efficient prediction of anticancer peptides through deep learning
Authors: Salam Abdu , Ullah Faizan , Amin Farhan , Ahmad Khan Izaz , Garcia Villena Eduardo , Kuc Castilla Angel , de la Torre Isabel
Published: July 2024

Background

Cancer remains one of the leading causes of mortality globally, with conventional chemotherapy often resulting in severe side effects and limited effectiveness. Recent advancements in bioinformatics and machine learning, particularly deep learning, offer promising new avenues for cancer treatment through the prediction and identification of anticancer peptides.

Objective

This study aimed to develop and evaluate a deep learning model utilizing a two-dimensional convolutional neural network (2D CNN) to enhance the prediction accuracy of anticancer peptides, addressing the complexities and limitations of current prediction methods.

Methods

A diverse dataset of peptide sequences with annotated anticancer activity labels was compiled from various public databases and experimental studies. The sequences were preprocessed and encoded using one-hot encoding and additional physicochemical properties. The 2D CNN model was trained and optimized using this dataset, with performance evaluated through metrics such as accuracy, precision, recall, F1-score, and area under the receiver operating characteristic curve (AUC-ROC).

Results

The proposed 2D CNN model achieved superior performance compared to existing methods, with an accuracy of 0.87, precision of 0.85, recall of 0.89, F1-score of 0.87, and an AUC-ROC value of 0.91. These results indicate the model’s effectiveness in accurately predicting anticancer peptides and capturing intricate spatial patterns within peptide sequences.

Conclusion

The findings demonstrate the potential of deep learning, specifically 2D CNNs, in advancing the prediction of anticancer peptides. The proposed model significantly improves prediction accuracy, offering a valuable tool for identifying effective peptide candidates for cancer treatment.

Future Work

Further research should focus on expanding the dataset, exploring alternative deep learning architectures, and validating the model’s predictions through experimental studies. Efforts should also aim at optimizing computational efficiency and translating these predictions into clinical applications.
Single-image super-resolution reconstruction based on phase-aware visual multi-layer perceptron (MLP)
Authors: Shi Changteng , Li Mengjun , An Zhiyong
Published: July 2024

Many advanced super-resolution reconstruction methods have been proposed recently, but they often require high computational and memory resources, making them incompatible with low-power devices in reality. To address this problem, we propose a simple yet efficient super-resolution reconstruction method using waveform representation and multi-layer perceptron (MLP) for image processing. Firstly, we partition the original image and its down-sampled version into multiple patches and introduce WaveBlock to process these patches. WaveBlock represents patches as waveform functions with amplitude and phase and extracts representative feature representations by dynamically adjusting phase terms between tokens and fixed weights. Next, we fuse the extracted features through a feature fusion block and finally reconstruct the image using sub-pixel convolution. Extensive experimental results demonstrate that SRWave-MLP performs excellently in both quantitative evaluation metrics and visual quality while having significantly fewer parameters than state-of-the-art efficient super-resolution methods.
Emotion brain network topology in healthy subjects following passive listening to different auditory stimuli
Authors: Mohd Rashid Muhammad Hakimi , Ab Rani Nur Syairah , Kannan Mohammed , Abdullah Mohd Waqiyuddin , Ab Ghani Muhammad Amiri , Kamel Nidal , Mustapha Muzaimi
Published: July 2024

A large body of research establishes the efficacy of musical intervention in many aspects of physical, cognitive, communication, social, and emotional rehabilitation. However, the underlying neural mechanisms for musical therapy remain elusive. This study aimed to investigate the potential neural correlates of musical therapy, focusing on the changes in the topology of emotion brain network. To this end, a Bayesian statistical approach and a cross-over experimental design were employed together with two resting-state magnetoencephalography (MEG) as controls. MEG recordings of 30 healthy subjects were acquired while listening to five auditory stimuli in random order. Two resting-state MEG recordings of each subject were obtained, one prior to the first stimulus (pre) and one after the final stimulus (post). Time series at the level of brain regions were estimated using depth-weighted minimum norm estimation (wMNE) source reconstruction method and the functional connectivity between these regions were computed. The resultant connectivity matrices were used to derive two topological network measures: transitivity and global efficiency which are important in gauging the functional segregation and integration of brain network respectively. The differences in these measures between pre- and post-stimuli resting MEG were set as the equivalence regions. We found that the network measures under all auditory stimuli were equivalent to the resting state network measures in all frequency bands, indicating that the topology of the functional brain network associated with emotional regulation in healthy subjects remains unchanged following these auditory stimuli. This suggests that changes in the emotion network topology may not be the underlying neural mechanism of musical therapy. Nonetheless, further studies are required to explore the neural mechanisms of musical interventions especially in the populations with neuropsychiatric disorders.
deepAMPNet: a novel antimicrobial peptide predictor employing AlphaFold2 predicted structures and a bi-directional long short-term memory protein language model
Authors: Zhao Fei , Qiu Junhui , Xiang Dongyou , Jiao Pengrui , Cao Yu , Xu Qingrui , Qiao Dairong , Xu Hui , Cao Yi
Published: July 2024

Background

Global public health is seriously threatened by the escalating issue of antimicrobial resistance (AMR). Antimicrobial peptides (AMPs), pivotal components of the innate immune system, have emerged as a potent solution to AMR due to their therapeutic potential. Employing computational methodologies for the prompt recognition of these antimicrobial peptides indeed unlocks fresh perspectives, thereby potentially revolutionizing antimicrobial drug development.

Methods

In this study, we have developed a model named as deepAMPNet. This model, which leverages graph neural networks, excels at the swift identification of AMPs. It employs structures of antimicrobial peptides predicted by AlphaFold2, encodes residue-level features through a bi-directional long short-term memory (Bi-LSTM) protein language model, and constructs adjacency matrices anchored on amino acids’ contact maps.

Results

In a comparative study with other state-of-the-art AMP predictors on two external independent test datasets, deepAMPNet outperformed in accuracy. Furthermore, in terms of commonly accepted evaluation matrices such as AUC, Mcc, sensitivity, and specificity, deepAMPNet achieved the highest or highly comparable performances against other predictors.

Conclusion

deepAMPNet interweaves both structural and sequence information of AMPs, stands as a high-performance identification model that propels the evolution and design in antimicrobial peptide pharmaceuticals. The data and code utilized in this study can be accessed at https://github.com/Iseeu233/deepAMPNet.
Validity of Wagner’s Law in Transition Economies: A Multivariate Approach
Authors: Balaban Suzana ,   Alfa BK University, Živkov Dejan ,   Novi Sad School of Business
Published: July 2024

We test the validity of Wagner’s law in transition countries using non-stationary panel estimators. First, we test cointegration between government final consumption expenditure and GDP, then we introduce the money supply as an additional explanatory variable. Finally, the Panel DOLS is used in order to estimate the long run relationship between the variables. According to our results, the government expenditure is an endogenous factor of an increase in national income. However, in observed economies in transition, there is reduction of public activity with the progress of the economy even in the case when a money supply is added.
Prioritizing National Security: A Prerequisite for Growth and Development in Nigeria
Authors: Samuel Umaru Tsaku
Published: July 2024

This article examines and analyzes concrete issues that undermine national security, growth and development in Nigeria. The paper maintained that national security is under serious threats emanating from the nature and character of the Nigerian State. The Nigerian State is reduced to a means of production by the hegemonic ruling faction, which is why the abundant human and natural resources have never been a spring board for socio-economic and political development, unable to liberate the Nigerian people from the shackles of poverty, unemployment, ignorance and disease in the midst of abundance thereby, generating insecurity. Today, insecurity has enveloped everywhere as communities have been taken over by insurgents and bandits who see criminality as a means of livelihood and sustenance. The streets have been taken over by kidnappers who abduct innocent citizens and demand for huge ransoms at the slightest opportunity. Majority of the people have no hope and confidence in the Nigerian State which is a theatre of accumulation and a depot of corruption by the political elite, who keep development at bay. The paper however concluded that for Nigeria to enjoy national security and to realize her potentials, deliberate efforts must be made to curb corruption which has been a monster that halted development over the years. Economic resources should be equitably distributed among the different ethnic groups who constitute Nigeria. Government must uphold the rule of law and ensure that justice is served to all who deserve it. Elections must not only be free and fair, but must be seen to be free and fair. Enduring institutions must be built by the state to stimulate development necessary to curb poverty, unemployment and ignorance which are catalysts for security crises in Nigeria.
Assessment of Genetic Variability in M3 Generation of Cowpea (Vigna unguiculata L. Walp)
Authors: Bagada Vikas Kumar , Jain S.K. , Yadav Giradhari Lal , Meena Ashok Kumar
Published: July 2024

The experiment material comprised of 150 mutant lines including two checks viz., RC-19 and RC-101 of cowpea to study genetic parameters for eleven characters. The estimates of PCV were found to be higher than estimates of GCV for all eleven characters it showing that the apparent variation is not only due to genotypes but also due to the influence of the environment. Higher GCV and PCV were observed for number of primary branches per plant and seed yield per plant. The estimates of heritability were observed to be higher for all the characters. Genetic advance as percentage of mean was higher observed for the number of primary branches per plant, seed yield per plant, number of seeds per pod, number of pods per plant, pod length, harvest index and biological yield per plant.
Seismic moment ratio of aftershocks with respect to main shocks
Authors: Zakharova O. , Hainzl S. , Bach C.
Published: November 2013

The empirical Båth's law indicates that the earthquake process is self‐similar and provides an opportunity to estimate the magnitude of the largest aftershock subsequent to a main shock. However, the analysis of this relation is limited to a small magnitude range and also depends on the aftershock selection rules. As an alternative, we analyze, in this paper, the cumulative seismic moment of aftershocks relative to the main shock moment, because (i) it is a physical quantity that does not only take the largest aftershock into account; (ii) background activity can be considered and as a result estimations are less affected by selection rules; and (iii) the effects of the catalog cut‐off magnitude can be corrected, what leads to larger magnitude range for the analysis. We analyze the global preliminary determination of epicenters U.S. Geological Society catalog (combined with centroid moment tensor focal mechanisms) and find that the seismic moment release of aftershocks is on average approximately 5% of the main shock seismic moment. We show that the results can be well fitted by simulations of the Epidemic Type Aftershock Sequence model. In particular, we test whether simulations constrained by predictions of the static stress‐triggering model, proposing a break of self‐similarity due to the finite seismogenic width, are in agreement with observations. Our analysis shows that the observed dependency on the main shock magnitude as well as systematic variations with the main shock fault plane solution can be both explained by the constraints based on the static stress triggering.
Low‐temperature magnetic properties of pelagic carbonates: Oxidation of biogenic magnetite and identification of magnetosome chains
Authors: Chang Liao , Winklhofer Michael , Roberts Andrew P. , Heslop David , Florindo Fabio , Dekkers Mark J. , Krijgsman Wout , Kodama Kazuto , Yamamoto Yuhji
Published: November 2013

Pelagic marine carbonates provide important records of past environmental change. We carried out detailed low‐temperature magnetic measurements on biogenic magnetite‐bearing sediments from the Southern Ocean (Ocean Drilling Program (ODP) Holes 738B, 738C, 689D, and 690C) and on samples containing whole magnetotactic bacteria cells. We document a range of low‐temperature magnetic properties, including reversible humped low‐temperature cycling (LTC) curves. Different degrees of magnetite oxidation are considered to be responsible for the observed variable shapes of LTC curves. A dipole spring mechanism in magnetosome chains is introduced to explain reversible LTC curves. This dipole spring mechanism is proposed to result from the uniaxial anisotropy that originates from the chain arrangement of biogenic magnetite, similar to published results for uniaxial stable single domain (SD) particles. The dipole spring mechanism reversibly restores the remanence during warming in LTC measurements. This supports a previous idea that remanence of magnetosome chains is completely reversible during LTC experiments. We suggest that this magnetic fingerprint is a diagnostic indicator for intact magnetosome chains, although the presence of isolated uniaxial stable SD particles and magnetically interacting particles can complicate this test. Magnetic measurements through the Eocene section of ODP Hole 738B reveal an interval with distinct magnetic properties that we interpret to originate from less oxidized biogenic magnetite and enrichment of a biogenic “hard” component. Co‐occurrence of these two magnetic fingerprints during the late Eocene in the Southern Ocean indicates less oxic conditions, probably due to increased oceanic primary productivity and organic carbon burial.
Nocturnal soil CO2 uptake and its relationship to subsurface soil and ecosystem carbon fluxes in a Chihuahuan Desert shrubland
Authors: Hamerlynck Erik P. , Scott Russell L. , Sánchez‐Cañete Enrique P. , Barron‐Gafford Greg A.
Published: November 2013

Despite their prevalence, little attention has been given to quantifying arid land soil and ecosystem carbon fluxes over prolonged, annually occurring dry periods. We measured soil [CO2] profiles and fluxes (Fs) along with volumetric soil moisture and temperature in bare interplant canopy soils and in soils under plant canopies over a three‐month hot and dry period in a Chihuahuan Desert shrubland. Nocturnal Fs was frequently negative (from the atmosphere into the soil), a form of inorganic carbon exchange infrequently observed in other deserts. Negative Fs depended on air‐soil temperature gradients and were more frequent and stronger in intercanopy soils. Daily integrated ecosystem‐level Fs was always positive despite lower daily Fs in intercanopy soils due to nocturnal uptake and more limited positive response to isolated rains. Subsurface [CO2] profiles associated with negative Fs indicated that sustained carbonate dissolution lowered shallow‐soil [CO2] below atmospheric levels. In the morning, positive surface Fs started earlier and increased faster than shallow‐soil Fs, which was bidirectional, with upward flux toward the surface and downward flux into deeper soils. These dynamics are consistent with carbonate precipitation in conjunction with convection‐assisted CO2 outgassing from warming air and soil temperatures and produced a pronounced diurnal Fs temperature hysteresis. We concluded that abiotic nocturnal soil CO2 uptake, through a small carbon sink, modulates dry season ecosystem‐level carbon dynamics. Moreover, these abiotic carbon dynamics may be affected by future higher atmospheric carbon dioxide levels and predictions of more prolonged and regular hot and dry periods.
Truths and myths about the determination of molar mass distribution of synthetic and natural polymers by size exclusion chromatography
Authors: Podzimek Stepan
Published: November 2013

This article discusses various aspects of the determination of molar mass distribution by means of size exclusion chromatography (SEC) in various application modes. The effects of erroneous specific refractive index increment (dn/dc), branching, column performance, and enthalpic interactions on the results obtained by different SEC techniques are discussed. Combination of SEC and a light scattering detector represents the most direct way to the molar mass distribution of all natural and synthetic polymers as it completely eliminates the need for column calibration and to a certain extent eliminates the dependence of the obtained results on some operational variables such as flow rate, temperature, or injected mass. A multiangle light scattering (MALS) photometer has become the most frequently used light scattering detector capable of determination of molecular size as another important polymer characteristic. This article contrasts SEC‐MALS method with other application modes of SEC from the viewpoint of some frequent confusions and misunderstandings. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40111.
Estimation of sea level pressure fields during Cyclone Nilam from Oceansat‐2 scatterometer winds
Authors: Purna Chand Ch. , Rao M. V. , Ramana I. V. , Ali M. M. , Patoux J. , Bourassa M. A.
Published: November 2013

Sea level pressure observations are rarely available over most of the oceans and no remote sensing instrument can measure it directly. Here, we explore the estimation of sea level pressure fields using surface wind observations from OSCAT, the scatterometer onboard Oceansat‐2, during the 27 October–2 November 2012 passage of Cyclone Nilam over the Bay of Bengal. The estimated pressure is validated with moored‐buoy observations. Scatterometer‐derived pressure differences are closer to in situ observations than those in examined numerical model estimations. The estimated pressure is more accurate than European Centre for Medium‐range Weather Forecasting re‐analysis values in location, track, and intensity.
Mobile phone use and risk of intracranial tumors: A consistency analysis
Authors: Lagorio Susanna , Röösli Martin
Published: November 2013

A meta‐analysis of studies on intracranial tumors and mobile phone use published by the end of 2012 was performed to evaluate the overall consistency of findings, assess the sensitivity of results to changes in the dataset, and try to detect the sources of between‐study heterogeneity. Twenty‐nine papers met our inclusion criteria. These papers reported on 47 eligible studies (17 on glioma, 15 on meningioma, 15 on acoustic neuroma), consisting of either primary investigations or pooled analyses. Five combinations of non‐overlapping studies per outcome were identified. The combined relative risks (cRRs) in long‐term mobile phone users (≥10 years) ranged between 0.98 (0.75–1.28) and 1.11 (0.86–1.44) for meningioma, with little heterogeneity across studies. High heterogeneity was detected across estimates of glioma and acoustic neuroma risk in long term users, with cRRs ranging between 1.19 (95% CI 0.86–1.64) and 1.40 (0.96–2.04), and from 1.14 (0.65–1.99) to 1.33 (0.65–2.73), respectively. A meta‐regression of primary studies showed that the methodological differences embedded in the variable “study‐group” explained most of the overall heterogeneity in results. Summary risk estimates based on heterogeneous findings should not be over‐interpreted. Overall, the results of our study detract from the hypothesis that mobile phone use affects the occurrence of intracranial tumors. However, reproducibility (or lack of) is just one clue in the critical appraisal of epidemiological evidence. Based on other considerations, such as the limited knowledge currently available on risk beyond 15 years from first exposure, or following mobile phone use started in childhood, the pursuance of epidemiological surveillance is warranted. Bioelectromagnetics. 35:79–90, 2014. © 2013 Wiley Periodicals, Inc.
Spatial organization of cell‐adhesive ligands for advanced cell culture
Authors: Ekerdt Barbara L. , Segalman Rachel A. , Schaffer David V.
Published: November 2013

Interaction between biomaterials and cells is a critical aspect for successful application of tissue engineering research. Technological advances within the past decade have enabled a number of studies to investigate how the spatial organization of cell‐adhesive ligands impacts complex and rich cell behaviors ranging from adhesion to differentiation. Cells in their native environment are surrounded by chemical and physical factors spanning a range of length scales from nanometers to hundreds of microns. Furthermore, signals in the form of cell‐adhesive ligands presented from this environment in different size scales and/or geometrical arrangements can change how a cell senses and responds to its surroundings. Biology can thus convey information not only in the concentration of a ligand but through its ability to change the spatial organization of these cues, raising questions both on the mechanisms by which it patterns such information and on the means by which a cell interprets it. This review discusses major findings associated with various systems developed to study cell‐adhesive ligand presentation as well as an overview of the important material systems used in these studies. Promising material systems to further investigations in this field are also examined. Future directions will likely include determining how cells sense local and global ligand concentrations, understanding underlying mechanisms that regulate cell behaviors, and investigating the function of more complex cell types and diverse ligands.
Design of affinity peptides from natural protein ligands: A study of the cardiac troponin complex
Authors: Chandra Divya , Sankalia Nitesh , Arcibal Imee , Banta Scott , Cropek Donald , Karande Pankaj
Published: November 2013

We describe a general strategy for the design and discovery of affinity peptides for a protein from its natural ligands. Our approach is guided by protein–protein interactions in natural systems and focuses on the hetero‐trimeric complex of cardiac troponin I (cTnI), C (cTnC) and T (cTnT). A key premise of this work is that cTnC and cTnT, owing to their innate ability to bind cTnI, are potential templates for the design and discovery of cTnI‐binding peptides. Relying only on the knowledge of primary sequences of cTnC and cTnT, we designed a library of short overlapping peptides that span the entirety of cTnC and cTnT and tested them for binding to cTnI. We were successful in identifying several peptides that display high affinity (1–100 nM) for cTnI. The specific implication of this work is that mimicking natural protein‐protein interactions is an excellent starting point for the discovery and rational design of peptide ligands. The knowledge of secondary or tertiary structures of the proteins involved is not a necessary precondition for this approach. Nevertheless, we show that structural information can be used to validate the results of a fragment‐based peptide design, and can be potentially beneficial for refining the lead candidates. Our approach is broadly applicable to any protein with at least one natural binding ligand with known primary sequence. For protein targets with multiple natural ligands, this approach can potentially yield several distinct affinity peptides capable of simultaneously binding the target protein via orthogonal modes or at complementary interfaces. © 2013 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 102: 97–106, 2014.
Translation of structure‐activity relationships from cyclic mixed efficacy opioid peptides to linear analogues
Authors: Anand Jessica P. , Porter‐Barrus Vanessa R. , Waldschmidt Helen V. , Yeomans Larisa , Pogozheva Irina D. , Traynor John R. , Mosberg Henry I.
Published: November 2013

Most opioid analgesics used in the treatment of pain are mu opioid receptor (MOR) agonists. While effective, there are significant drawbacks to opioid use, including the development of tolerance and dependence. However, the coadministration of a MOR agonist with a delta opioid receptor (DOR) antagonist slows the development of MOR‐related side effects, while maintaining analgesia. We have previously reported a series of cyclic mixed efficacy MOR agonist/DOR antagonist ligands. Here we describe the transfer of key features from these cyclic analogs to linear sequences. Using the linear MOR/DOR agonist, Tyr‐DThr‐Gly‐Phe‐Leu‐Ser‐NH2 (DTLES), as a lead scaffold, we replaced Phe4 with bulkier and/or constrained aromatic residues shown to confer DOR antagonism in our cyclic ligands. These replacements failed to confer DOR antagonism in the DTLES analogs, presumably because the more flexible linear ligands can adopt binding poses that will fit in the narrow binding pocket of the active conformations of both MOR and DOR. Nonetheless, the pharmacological profile observed in this series, high affinity and efficacy for MOR and DOR with selectivity relative to KOR, has also been shown to reduce the development of unwanted side effects. We further modified our lead MOR/DOR agonist with a C‐terminal glucoserine to improve bioavailability. The resulting ligand displayed high efficacy and potency at both MOR and DOR and no efficacy at KOR. © 2013 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 102: 107–114, 2014.
Enzyme‐driven bacillus spore coat degradation leading to spore killing
Authors: Mundra Ruchir V. , Mehta Krunal K. , Wu Xia , Paskaleva Elena E. , Kane Ravi S. , Dordick Jonathan S.
Published: November 2013

The bacillus spore coat confers chemical and biological resistance, thereby protecting the core from harsh environments. The primarily protein‐based coat consists of recalcitrant protein crosslinks that endow the coat with such functional protection. Proteases are present in the spore coat, which play a putative role in coat degradation in the environment. However these enzymes are poorly characterized. Nonetheless given the potential for proteases to catalyze coat degradation, we screened 10 commercially available proteases for their ability to degrade the spore coats of B. cereus and B. anthracis. Proteinase K and subtilisin Carlsberg, for B. cereus and B. anthracis spore coats, respectively, led to a morphological change in the otherwise impregnable coat structure, increasing coat permeability towards cortex lytic enzymes such as lysozyme and SleB, thereby initiating germination. Specifically in the presence of lysozyme, proteinase K resulted in 14‐fold faster enzyme induced germination and exhibited significantly shorter lag times, than spores without protease pretreatment. Furthermore, the germinated spores were shown to be vulnerable to a lytic enzyme (PlyPH) resulting in effective spore killing. The spore surface in response to proteolytic degradation was probed using scanning electron microscopy (SEM), which provided key insights regarding coat degradation. The extent of coat degradation and spore killing using this enzyme‐based pretreatment approach is similar to traditional, yet far harsher, chemical decoating methods that employ detergents and strong denaturants. Thus the enzymatic route reduces the environmental burden of chemically mediated spore killing, and demonstrates that a mild and environmentally benign biocatalytic spore killing is achievable. Biotechnol. Bioeng. 2014;111: 654–663. © 2013 Wiley Periodicals, Inc.
Enhancing E. coli isobutanol tolerance through engineering its global transcription factor cAMP receptor protein (CRP)
Authors: Chong Huiqing , Geng Hefang , Zhang Hongfang , Song Hao , Huang Lei , Jiang Rongrong
Published: November 2013

The limited isobutanol tolerance of Escherichia coli is a major drawback during fermentative isobutanol production. Different from classical strain engineering approaches, this work was initiated to improve E. coli isobutanol tolerance from its transcriptional level by engineering its global transcription factor cAMP receptor protein (CRP). Random mutagenesis libraries were generated by error‐prone PCR of crp, and the libraries were subjected to isobutanol stress for selection. Variant IB2 (S179P, H199R) was isolated and exhibited much better growth (0.18 h−1) than the control (0.05 h−1) in 1.2% (v/v) isobutanol (9.6 g/L). Genome‐wide DNA microarray analysis revealed that 58 and 308 genes in IB2 had differential expression (>2‐fold, p < 0.05) in the absence and presence of 1% (v/v) isobutanol, respectively. When challenged with isobutanol, genes related to acid resistance (gadABCE, hdeABD), nitrate reduction (narUZYWV), flagella and fimbrial activity (lfhA, yehB, ycgR, fimCDF), and sulfate reduction and transportation (cysIJH, cysC, cysN) were the major functional groups that were up‐regulated, whereas most of the down‐regulated genes were enzyme (tnaA) and transporters (proVWX, manXYZ). As demonstrated by single‐gene knockout experiments, gadX, nirB, rhaS, hdeB, and ybaS were found associated with strain isobutanol resistance. The intracellular reactive oxygen species (ROS) level in IB2 was only half of that of the control when facing stress, indicating that IB2 can withstand toxic isobutanol much better than the control. Biotechnol. Biotechnol. Bioeng. 2014;111: 700–708. © 2013 Wiley Periodicals, Inc.
Initial experience with the glidesheath slender for transradial coronary angiography and intervention: A feasibility study with prospective radial ultrasound follow‐up
Authors: Aminian Adel , Dolatabadi Dariouch , Lefebvre Pascal , Zimmerman Robert , Brunner Philippe , Michalakis Georges , Lalmand Jacques
Published: November 2013

Objective

The aim of this study is to evaluate the feasibility and safety of the Glidesheath Slender in routine transradial (TR) coronary angiography and intervention.

Background

In recent years, The TR approach has gained in popularity because of several advantages such as reduced vascular access site complications and immediate patient mobilization. Procedural success has been further improved through technological innovations and the development of less invasive devices. The Glidesheath Slender (Terumo, Tokyo, Japan) is a new dedicated radial sheath with a thinner wall and hydrophilic coating. It combines an inner diameter compatible with 6Fr guiding catheter with an outer diameter close to current 5Fr sheaths. Its use has the potential to decrease invasiveness and access site complications during TR procedures.

Methods

A total of 114 consecutive patients undergoing TR coronary angiography and/or PCI using the Gidesheath Slender were included in a prospective single‐center feasibility and safety study.

Results

Procedural success was 99.1% with only one case requiring conversion to femoral access. There were six minor hematomas but none of the patients experienced major vascular complications. The rate of symptomatic radial spasm was 4.4%. No case of major sheath kinking was noted. Doppler ultrasound examination of the radial artery at 1 month follow‐up was available in 113/114 patients with only one case of radial artery occlusion (RAO) (0.88%).

Conclusions

Routine use of the Glidesheath Slender for TR coronary angiography and interventions is safe and feasible with a high rate of procedural success and a low rate of RAO. © 2013 Wiley Periodicals, Inc.
Transesterifications and Peracid‐Assisted Oxidations in Aqueous Media Catalyzed by Mycobacterium smegmatis Acyl Transferase
Authors: Wiermans Lotte , Hofzumahaus Sebastian , Schotten Christiane , Weigand Lisa , Schallmey Marcus , Schallmey Anett , Domínguez de María Pablo
Published: November 2013

Hydrolases catalyze synthetic reactions in nonaqueous media, whereas they perform hydrolysis under aqueous solutions. An acyl transferase from Mycobacterium smegmatis (MsAcT) is able to catalyze synthetic reactions in buffer because of its highly hydrophobic active site, which enables efficient transesterification reactions even at 99.9 % v/v buffer solution. This unique feature of MsAcT among hydrolases may open new opportunities to conduct synthetic (bio)catalysis in aqueous media. With these goals in mind, this paper explores some evidence of such potential: MsAcT can perform enantioselective transesterifications (e.g., (S)‐2‐octanol), which could be combined with other aqueous multistep (asymmetric) reactions; 5‐hydroxymethylfurfural (HMF) can be esterified to produce more hydrophobic and easily extractable HMF esters (e.g., for downstream processing or wastewater treatment); and upon addition of dilute H2O2, MsAcT works efficiently as a perhydrolase to form in situ peracids—in bulk water—that can be used for oxidations (e.g., furfural to furoic acid oxidation). Overall, these and many other new applications can be envisaged by using MsAcT in aqueous solutions.
Ruthenium(II)‐catalysed Functionalisation of CH Bonds via a Six‐membered Cyclometallate: Monoarylation of Aryl 2‐pyridyl Ketones
Authors: Li Bin , Darcel Christophe , Dixneuf Pierre H.
Published: November 2013

Selective monoarylation of aryl 2‐pyridyl ketones with a variety of arylbromides via arene sp2 CH bond activation/functionalisation is achieved with a [RuCl2(p‐cymene)]2/ p‐CF3C6H4CO2H catalytic system. The reaction via a 6‐membered ruthenacycle is more difficult to perform than via a 5‐membered cyclometallate but the activation of only one ortho CH bond is unprecedentedly highly selective. A variety of functional 2‐pyridine derivatives are easily obtained. It is shown via H/D exchange that the carboxylic acid favours the reversible CH bond activation.
Fourier‐Transformed Large‐Amplitude AC Voltammetric Study of Tetrathiafulvalene (TTF): Electrode Kinetics of the TTF0/TTF.+ and TTF.+/TTF2+ Processes
Authors: Bond Alan M. , Bano Kiran , Adeel Shaimaa , Martin Lisandra L. , Zhang Jie
Published: November 2013

Large‐amplitude Fourier‐transformed (FT) AC voltammetry was used at high frequency to study the electrode kinetics of tetrathiafulvalene (TTF), its radical cation TTF.+ and that of the dication TTF2+ in acetonitrile (0.1 M Bu4NPF6). The two oxidized forms were prepared by quantitative bulk electrolysis of TTF under dry‐box conditions. A high frequency of 233 Hz was used at glassy carbon (GC) and platinum (Pt) macro disk electrodes to enhance the kinetic sensitivity and hence upper limit of the measurable heterogeneous charge transfer rate constant (k0). Difficulties associated with the use of high frequencies at macro disk electrodes are discussed. Comparison of experimental data with simulations is used to extract k0 and other parameters for each of the TTF0/.+ and TTF.+/2+ processes from both reduction and oxidation perspectives. k0 values for TTF0/.+and TTF.+/0 processes are ≥1.0 cm s−1 and consequently regarded as reversible under the AC conditions used. However, the significantly slower quasi‐reversible behaviour observed for the TTF.+/2+ redox couple, with k0 being 0.3±0.05 cm s−1, can be precisely estimated.