bluuebunny/crossref_metadata_2025 huggingface dataset:
Pralatrexate in Combination with Oxaliplatin in Advanced Esophagogastric Cancer: A Phase II Trial with Predictive Molecular Correlates
Authors: Malhotra Usha , Mukherjee Sarbajit , Fountzilas Christos , Boland Patrick , Miller Austin , Patnaik Santosh , Attwood Kristopher , Yendamuri Sai , Adjei Araba , Kannisto Eric , Opyrchal Mateusz , Bushunow Peter , Loud Peter , Iyer Renuka , Khushalani Nikhil
Published: October 2019

The purpose of our study was to evaluate the efficacy of a combination of pralatrexate plus oxaliplatin in advanced esophagogastric cancer (EGC), analyze the impact of polymorphisms in folate metabolism pathway genes on toxicity and efficacy of pralatrexate, and to evaluate microRNA profile of tumor epithelium as a predictive biomarker. This was a two-stage trial with a safety lead in cohort and a primary endpoint of overall response rate (ORR). Patients received biweekly intravenous oxaliplatin (85 mg/m2) and pralatrexate (Dose level 1 [D1], 120 mg/m2; dose level-1 [D-1] 100 mg/m2). Single-nucleotide polymorphisms (SNP) in genes encoding proteins involved in pralatrexate metabolism were evaluated in germline DNA. microRNA profiling of the tumor epithelium was performed. ORR was 26%. Dose-limiting toxicities were observed in 2 of 4 patients at D1 and none at D-1. The T>C polymorphism in DHFR rs11951910 was significantly associated with lower progression-free survival (PFS; P ≤ 0.01), whereas the presence of the SLC19A1 rs2838957 G>A polymorphism was associated with improved PFS (P = 0.02). Presence of the GGH rs3780130 A>T and SLC19A1 rs1051266 G>A polymorphisms were significantly associated with better overall survival (OS; P = 0.01), whereas GGH rs7010484 T>C polymorphism was associated significantly with reduced OS (P = 0.04). There was no correlation between epithelial microRNA expression profile with disease progression or response. We conclude that the combination of oxaliplatin and pralatrexate is safe, is well tolerated, and has modest efficacy in advanced EGC. Pharmacogenomic analysis may be relevant to the use of pralatrexate in combination with platinum agents.
Targeting Histone Chaperone FACT Complex Overcomes 5-Fluorouracil Resistance in Colon Cancer
Authors: Song Heyu , Zeng Jiping , Roychoudhury Shrabasti , Biswas Pranjal , Mohapatra Bhopal , Ray Sutapa , Dowlatshahi Kayvon , Wang Jing , Band Vimla , Talmon Geoffrey , Bhakat Kishor K.
Published: October 2019

Fluorouracil (5-FU) remains a first-line chemotherapeutic agent for colorectal cancer. However, a subset of colorectal cancer patients who have defective mismatch-repair (dMMR) pathway show resistance to 5-FU. Here, we demonstrate that the efficacy of 5-FU in dMMR colorectal cancer cells is largely dependent on the DNA base excision repair (BER) pathway. Downregulation of APE1, a key enzyme in the BER pathway, decreases IC50 of 5-FU in dMMR colorectal cancer cells by 10-fold. Furthermore, we discover that the facilitates chromatin transcription (FACT) complex facilitates 5-FU repair in DNA via promoting the recruitment and acetylation of APE1 (AcAPE1) to damage sites in chromatin. Downregulation of FACT affects 5-FU damage repair in DNA and sensitizes dMMR colorectal cancer cells to 5-FU. Targeting the FACT complex with curaxins, a class of small molecules, significantly improves the 5-FU efficacy in dMMR colorectal cancer in vitro (∼50-fold decrease in IC50) and in vivo xenograft models. We show that primary tumor tissues of colorectal cancer patients have higher FACT and AcAPE1 levels compared with adjacent nontumor tissues. Additionally, there is a strong clinical correlation of FACT and AcAPE1 levels with colorectal cancer patients' response to chemotherapy. Together, our study demonstrates that targeting FACT with curaxins is a promising strategy to overcome 5-FU resistance in dMMR colorectal cancer patients.
Does Oxygen Stable Isotope Composition in Primates Vary as a Function of Vertical Stratification or Folivorous Behaviour?
Authors: Fannin Luke D. , Scott McGraw W.
Published: October 2019

Stable isotopes of oxygen often vary within a community of primates. For example, folivorous monkeys that forage in the upper reaches of the forest canopy tend to evince high δ18O values, whereas those that prefer the understory tend to have lower δ18O values. Given that leaves also have high δ18O values, particularly higher in the canopy, there is uncertainty as to which behavioural variable – vertical stratification or folivory – is the primary determinant of variation in δ18O values. Here, we explore further δ18O values from the Taï Forest monkeys (n = 7 species; n = 33 individuals) by examining the interaction between diet and vertical stratification, thereby allowing us to differentiate the effects of each covariate. We found that δ18O values varied as a function of mean canopy height, but not folivory, resolving uncertainty about the primary cause of δ18O variation. This outcome revolves largely, but not entirely, on the behaviours of Procolobus verus, a highly folivorous but understory forager. Relatively elevated values in Cercopithecus diana, a frugivorous but middle-to-high canopy forager, raises the possibility that plant reproductive tissues (e.g., fruits, flowers) may be increasingly sensitive to evaporative fractionation at higher forest canopy levels. Overall, our results further affirm the value of using δ18O values to estimate the vertical behaviour of primate species in a fossil assemblage.
Myeloid SOCS3 Deficiency Regulates Angiogenesis via Enhanced Apoptotic Endothelial Cell Engulfment
Authors: Korovina Irina , Neuwirth Ales , Sprott David , Troullinaki Maria , Poitz David M. , Deussen Andreas , Klotzsche-von Ameln Anne
Published: October 2019

Mononuclear phagocytes, such as macrophages and microglia, are key regulators of organ homeostasis including vascularization processes. Here, we investigated the role of the suppressor of cytokine signaling 3 (SOCS3) in myeloid cells as a regulator of mononuclear phagocyte function and their interaction with endothelial cells in the context of sprouting angiogenesis. As compared to SOCS3-sufficient counterparts, SOCS3-deficient microglia and macrophages displayed an increased phagocytic activity toward primary apoptotic endothelial cells, which was associated with an enhanced expression of the opsonin growth arrest-specific 6 (Gas6), a major prophagocytic molecule. Furthermore, we found that myeloid SOCS3 deficiency significantly reduced angiogenesis in an ex vivo mouse aortic ring assay, which could be reversed by the inhibition of the Gas6 receptor Mer. Together, SOCS3 in myeloid cells regulates the Gas6/Mer-dependent phagocytosis of endothelial cells, and thereby angiogenesis-related processes. Our findings provide novel insights into the complex crosstalk between mononuclear phagocytes and endothelial cells, and may therefore provide a new platform for the development of new antiangiogenic therapies.
Clinical Features and the Validation of the Brighton Criteria in Guillain-Barré Syndrome: Retrospective Analysis of 72 Hospitalized Patients in Three Years
Authors: Zeng Yanping , Liu Yin , Xie Yanchun , Liang Jingjing , Xiao Zheman , Lu Zuneng
Published: October 2019

Objective: To analyze the clinical phenotypes and features of Guillain-Barré syndrome (GBS) in our hospital and explore the diagnostic value of the Brighton criteria. Methods: We retrospectively analyzed the clinical data of GBS patients hospitalized in our hospital from January 1, 2013, to September 30, 2016. The patients were affirmatively graded according to the Brighton criteria (highest: level 1, lowest: level 4). Result: (1) We enrolled 72 patients with GBS, including 7 with cranial nerve variants, 4 with Miler-Fisher syndrome, and 61 with classic GBS that mainly presented as limb weakness. (2) A total of 56.94% of the included patients had preceding events, of which respiratory tract infections accounted for 63.41%; there was a significant difference in the incidence of GBS across the spring, summer, autumn, and winter. Weakness was the first symptom in 75% of patients, all patients reached peaked within 4 weeks, and 94.44% of the patients presented with decreased or absent deep tendon reflexes. Among the patients who completed a lumbar puncture cerebrospinal fluid (CSF) examination, 73.24% showed proteins dissociated from CSF cells. Demyelinating GBS was found in 54%, and axonal GBS was found in 22% of the patients who completed an electrophysiological examination. All patients with classic GBS were graded according to the Brighton diagnostic criteria as level 1 (60.66%, 37/61), level 2 (34.42%, 21/61), level 3 (4.92%, 3/61), or level 4 (0%). Conclusion: In our hospital, the clinical features of patients with GBS were similar to those described in previous studies, but demyelinating GBS was the most important subtype. Most preceding events were upper respiratory tract infections. The Brighton criteria were highly sensitive, and perfect clinical data improved diagnostic grading. In areas where medical resources are relatively scarce, a detailed medical history and physical examination can help improve diagnostic accuracy.
Endoscopic Resection of a Pedunculated Cavernous Hemangioma of the Sigmoid Colon: A Case Report
Authors: Ogasawara Naotaka , Suzuki Manami , Adachi Kazunori , Yamaguchi Yoshiharu , Yamamoto Sayuri , Hijikata Yasutaka , Ebi Masahide , Funaki Yasushi , Sasaki Makoto , Kasugai Kunio
Published: October 2019

Hemangiomas are common benign tumors that usually occur on the head and neck in children. However, colonic hemangiomas are rare in clinical practice. Approximately 80% of colonic hemangiomas are of the cavernous type, and morphologically, ≥80% of colonic hemangiomas are sessile and semi-pedunculated. Notably, pedunculated colonic hemangiomas are rare. A 69-year-old woman presented with hematochezia and underwent colonoscopy, which revealed a soft pedunculated submucosal tumor (SMT) measuring 1.5 cm in diameter, in the sigmoid colon. The surface of the SMT resembled the surrounding normal colonic mucosa with regard to color and appearance, with multiple red patches. Narrow-band imaging revealed a few telangiectasias on the surface of the SMT. The lesion could not be definitively diagnosed based on endoscopic findings. Therefore, for more accurate diagnosis, the SMT was removed by snare polypectomy with electrocautery after clipping the basal portion of the tumor stalk for prophylactic hemostasis. Histopathological examination of the specimen revealed a cavernous hemangioma with a negative resection margin. We report a case of a pedunculated cavernous hemangioma of the sigmoid colon removed by snare polypectomy with electrocautery after clipping the basal portion of the tumor stalk for prophylactic hemostasis.
Threat, its impacts over survival systems, and related behavioral disorders
Authors: Carui Nickolas , Almeida Luis Fernando De , Miglioranza Gabriela , Corchs Felipe
Published: October 2019

Defensive and appetitive motivation systems have evolved to propitiate more sophisticated interactions with environment threats and needs, such as nutrients, water, reproduction, and temperature regulation. In contact with survival-relevant environmental stimuli, organisms change as a whole to maximize fitness to that occasion. In this paper, an overview on defensive systems is described, as well as some relevant aspects of defensive states, including their impacts over appetitive functions. A parallel between these characteristics and what is called threat-related disorders in the present paper is drawn and, finally, these similarities are used as basis for a theoretical proposition that at least part of these disorders can be seen as persistent states of defense.
Theoretical models of Obsessive-Compulsive Disorder (OCD)
Authors: Farhat Luis C. , Saraiva Leonardo , Hoexter Marcelo Q. , Miguel Euripedes C.
Published: October 2019

Obsessive-Compulsive disorder (OCD) is a common psychiatric condition that leads to significant impairment in everyday life. Advancements in neurobiological investigations contributed to a better understanding of pathophysiological mechanisms behind OCD, leading to the understanding that current models employed to conceptualize OCD are not adequate and might be a significant factor in precluding further advancements in how OCD is treated. In this paper, we will use OCD as a model to discuss the limitations of the current diagnostic systems in Psychiatry and to present the novel perspectives based on neurobiological findings that might lead to considerable advancements in treatments for OCD.
Non-invasive brain stimulation therapies
Authors: Suen Paulo J. C. , Brunoni Andre R.
Published: October 2019

Noninvasive brain stimulation therapies are a promising field for the development of new protocols for the treatment of neuropsychiatric disorders. They are based on the stimulation of neural networks with the intent of modeling their synaptic activity to adequate levels. For this, it is necessary to precisely determine which networks are related to which brain functions, and the normal activation level of each of these networks, so that it is possible to direct the stimulation to the affected networks in order to induce the desired effects. These relationships are under intense investigation by the scientific community, and will contribute to the advancement of treatments by neurostimulation, with the emergence of increasingly accurate and effective protocols for different disorders. Currently, the most used techniques are Transcranial Direct Current Stimulation and Transcranial Magnetic Stimulation, with the most common applications being for treating Major Depressive Disorder. The advancement of research in this field may determine new target networks for stimulation in the treatment of other disorders, extending the application of these techniques and also our knowledge about brain functioning.
Mesobiotus datanlanicus sp. nov., a new tardigrade species (Macrobiotidae: Mesobiotus harmsworthi group) from Lâm Đồng Province in Vietnam
Authors: STEC DANIEL
Published: October 2019

A new species of the Mesobiotus harmsworthi group is described from Datanla Waterfall amusement park in Lâm Đồng Province, Vietnam. An integrative taxonomy approach was applied, by combining morphological and morphometric analyses using light contract microscopy (LCM)) and scanning electron microscopy (SEM) with genetic analysis (18S rRNA, 28S rRNA, ITS-2 and COI markers), to cross-verify the status of the newly discovered population as a new species. By the presence of fully developed areolation around egg processes bases and well developed oral cavity armature (OCA), with all three bands of teeth visible under (LCM), the new species, Mesobiotus datanlanicus sp. nov., is most similar to seven taxa from the harmsworthi complex: M. barbarae (Kaczmarek, Michalczyk & Degma, 2007), M. hieronimi (Pilato & Claxton, 1988), M. insanis Mapalo, Stec, Mirano-Bascos & Michalczyk, 2017, M. neuquensis (Rossi, Claps & Ardohain, 2009), M. nuragicus (Pilato & Sperlinga, 1975), M. pseudoliviae (Pilato & Binda, 1996), M. pseudonuragicus (Pilato, Binda, & Lisi, 2004), but differs from them mainly by some specific characters of the egg and adult morphology as well as by morphometrics.
Designation of a neotype for Glypturus rabalaisae Sakai, 2011, a ghost shrimp from continental shelf waters of the northern Gulf of Mexico (Crustacea: Decapoda: Callianassidae)
Authors: FELDER DARRYL L.
Published: October 2019

Glypturus rabalaisae Sakai, 2011 was named for type materials identified solely on the basis of illustrations that had been originally reported as “Glypturus acanthochirus” by previous authors (Rabalais et al. 1981). As the voucher specimens for those illustrations (thus the types) are lost, a neotype is designated. “Glypturus rabalaisae” as originally applied by Sakai (2005) constituted a nomen nudum, and the name has debatably remained so regarded, since the description in Sakai (2011) failed to clearly account for disposition of a type. In the interest of stability, his 2011 description is herewith regarded to meet minimum ICZN requirements for validity, and the name is conserved. Synonymies, brief diagnoses, and updated ranges are provided for Glypturus rabalaisae and its only known regional congener, G. acanthochirus Stimpson, 1866. Available illustrations of G. rabalaisae are augmented by color photographs.
Taxonomic study of the genus Blastobasis Zeller, 1855 (Lepidoptera: lastobasidae) from China, with descriptions of six new species
Authors: TENG KAIJIAN , WANG SHUXIA
Published: October 2019

The ten species of the genus Blastobasis Zeller, 1855 recorded from Mainland China are reviewed, of which six are described as new: B. spinisetosa, sp. nov., B. divulgata, sp. nov., B. adamskii, sp. nov., B. aciformis, sp. nov., B. edentula, sp. nov., and B. hamata, sp. nov. Blastobasis parki Sinev, 1986 and B. inouei Moriuti, 1987 are recorded for the first time in China. Images of adults and genitalia are provided. A key to the species of Mainland China and a map showing their distributions are included.
New species of the genus Trechus Clairville, 1806 from the Chinese Tien Shan (Coleoptera: Carabidae)
Authors: BELOUSOV IGOR A. , KABAK ILYA I.
Published: October 2019

Five new species of the genus Trechus Clairville, 1806 are described from the eastern part of the Tien Shan mountains (China, Xinjiang-Uygur Autonomous Region): T. tsanmensis sp. n. from the Narat Mountain Range, left bank of the Zanma River; T. torgaut sp. n. from the upper course of the Kunges River and Narat Mountain Range (both species belong to the uygur species group, which is defined here); T. aghiazicus sp. n. from the Aghiaz River and Koeksu Basin, T. cratocephalus sp. n. from the Narat Mountain Range (both belong to the micrangulus species group); and T. saluki sp. n. from the mountains S of the Kunges River (belonging to the kashensis species group, also defined in the present paper). Some new data on the distribution of T.uygur Deuve, 1993 and T. kashensis Belousov & Kabak, 2001 are given. The distribution of all known species of the uygur and kashensis groups is mapped. An identification key is provided to known species of the uygur group.
Gastrointestinal nematodes of Paramelomys platyops (Rodentia: Muridae) from Papua Indonesia and Papua New Guinea with the descriptions of a new genus and five new species of Heligmonellidae (Nematoda: Trichostrongylina) and a key to the species of Hughjonestrongylus
Authors: SMALES LESLEY
Published: October 2019

Nematodes from six families, comprising 20 species identified to genus level and three to subfamily level as well as juveniles and a heligmonellid that could not be identified further, were recovered from 34 individuals of Paramelomys platyops, one P. cf playops and one Melomys sp. (Muridae: Murinae: Uromys Division) from Papua Indonesia and Papua New Guinea. Ascaridid larvae, a capillariid, Capillaria s. l., two putative species of the Nippostrongylinae and a small number of heligmonellid males and females, could not be identified further. The rictulariid Pterygodermatites sp. (females only) had not been reported previously from Sahulan Old Endemic fauna while three species, the oxyurid Syphacia longecauda , the molineid Hepatojarakus pyknofasciatus, and the spirurid Protospirura kaindiensis, had. The remaining species, all heligmonellids, included the brevistriatine Macrostrongylus ingens and 14 nippostrongyline species. Of these, Hughjonestrongylus amplicauda, H. singauwaensis, Melomystrongylus sepikensis, Mawsonema mokwanense, Odilia mackerrasae and Parasabanema szalayi had been reported previously. Species of Hasanuddina, Montistrongylus and Sanduanensis possibly as yet undescribed, could not be identified further. Flannerystrongylus abulus n. gen., n. sp. differed from all 41 genera described to date in having a synlophe of 14–16 evenly sized ridges with a sub frontal orientation. Hasegawanema yuroense n. sp. with 21–23 synlophe ridges was distinguished from its congeners by a combination of characters including length of spicule, cuticularisation of the genital cone, the proportions of the ovejector and the size of the eggs. Hughjonestrongylus pervulgatus n. sp., H. vanimoensis n. sp. and H. wanumaensis n. sp. were distinguished from all other species of Hughjonestrongylus and each other by a combination of characters including the number of synlophe ridges 25–30, 18, 22–23 in the mid body respectively, and spicule length, proportions of the ovejector and shape of the female tail. A key to the species of Hughjonestrongylus is provided. Species richness was greater than that recorded for P. lorentzii and P. rubex with about 86% of possible species found, as indicated by bootstrap analysis. The helminth assemblage was dominated by heligmonellids with eight species being unique to P. platyops. Paramelomys lorentzii is found at altitudes up to 1500 m and may provide a link between the lowland P. platyops and the highland P. rubex, thus facilitating the distribution of helminth species held in common.
Taxonomy of Neotropical genera Compsodactylus and Dasyus and notes on claw movement in Macrodactylini (Coleoptera: Scarabaeidae: Melolonthinae)
Authors: FUHRMANN JUARES
Published: October 2019

A taxonomic review of Dasyus LePeletier & Audinet-Serville, 1828 is provided and the classification of Compsodactylus Fuhrmann, 2012 is updated (Coleoptera: Scarabaeidae: Melolonthinae: Macrodactylini). Lectotypes are designated for the following names: Dasyus collaris luridipennis Moser, 1918, Dasyus variabilis Moser, 1918 and Isonychus argentinus Moser, 1919. Compsodactylus argentinus (Moser, 1919) is a new combination to the species formerly placed in Isonychus Mannerheim, 1829. The following four synonymies are proposed: C. scabrosus Fuhrmann, 2012 is a new synonym of C. argentinus; Dasyus fulvipennis Blanchard, 1850 and Dicrania hirsuta Frey, 1970 are both new synonyms of Dasyus collaris LePeletier & Audinet-Serville, 1828; and Calodactylus pilicollis Frey, 1974 is a new synonym of D. variabilis. Two synonymies formerly proposed but sometimes omitted are here confirmed: D. nigellus Blanchard, 1850 and D. collaris luridipennis synonymies of D. collaris. The male of Compsodactylus parvulus (Frey, 1970) is described for the first time. Diagnoses, keys, distributional data, and a discussion about macrodactyline tarsal claws are included.
Effects of OSA Surgery on Leptin and Metabolic Profiles
Authors: Chin Chien‐Hung , Lin Pei‐Wen , Lin Hsin‐Ching , Friedman Michael , Lin Meng‐Chih
Published: October 2019

Objectives

This study is designed to investigate the effects of obstructive sleep apnea/hypopnea syndrome (OSA) surgery on serum leptin levels and metabolic disturbances, both of which contribute to the risk of cardiovascular diseases.

Study Design

Case series with planned data collection.

Setting

Tertiary referral medical center.

Subjects and Methods

A retrospective chart review of 101 consecutive patients with OSA who refused or failed conservative therapy and who then underwent upper airway surgery for OSA treatment was conducted. The personal medical history, anthropometric measurements, subjective symptoms, and objective polysomnographic parameters and fasting morning blood samples for leptin and metabolic biomarkers measurements were collected preoperatively and at a minimum of 3 months postoperatively.

Results

Eighty patients with OSA (69 men and 11 women; mean [SD] age of 42.2 [10.2] years) with complete data were included in the final analysis. At least 3 months after surgery, serum leptin, low‐density lipoprotein cholesterol (LDL‐C), and triglyceride levels and the mean systolic blood pressure (SBP) (night and morning) significantly decreased. According to the classical definition of surgical success, 40 subjects had successful surgery and were categorized as surgical responders, and the other 40 patients who failed surgery were categorized as surgical nonresponders. Significant reductions in serum leptin, total cholesterol, LDL‐C, and triglyceride levels and improvement of mean SBP (morning) occurred in surgical responders but not in nonresponders.

Conclusions

Effective OSA surgery improves serum leptin, lipid profiles, and SBP. Further studies are needed to investigate the role of serial measurements of these biomarkers in monitoring surgical outcome of OSA treatment.
Surgical Explantation of Bone‐Anchored Hearing Devices: A 10‐year Single Institution Review
Authors: Fritz Christian G. , Bojrab Dennis I. , Lin Kenny F. , Schutt Christopher A. , Babu Seilesh C. , Hong Robert S.
Published: October 2019

Objective

To identify clinical variables associated with the decision to surgically discontinue bone‐anchored hearing device function.

Study Design

Retrospective chart review.

Setting

Tertiary neurotology referral center.

Subjects and Methods

This study examines surgical interventions performed on existing bone‐anchored hearing devices at a single institution from 2008 to 2018. Patient characteristics, indications for implantation, and complications prompting surgical intervention were assessed.

Results

Seventy‐seven cases were included in this study. Among patients in the younger cohort (<37 years old), 100% (13 of 13) of those discontinuing their device had a contralateral normal‐hearing ear. Conversely, 0% (0 of 14) of the younger patients with bilateral hearing loss surgically discontinued their devices. Within the older cohort (≥37 years old), female patients (P =. 002) and those with an increased body mass index (P =. 035) were more likely to surgically discontinue their devices. Multivariate analysis revealed that a contralateral normal‐hearing ear (P =. 001) and infection without soft tissue overgrowth of the abutment (P =. 026) were the strongest predictors of device discontinuation, after adjusting for potential confounders.

Conclusion

Surgical discontinuation is associated with several clinical variables. Targeted interventions that are viable alternatives to removal, such as device relocation, should be presented to younger patients with a contralateral normal‐hearing ear who experience persistent complications. Patients with persistent infection in the absence of soft tissue overgrowth would especially benefit from enhanced counseling on proper hygiene.
An Analysis of China and Africa Relations with Special Focus on ‘One Belt and One Road’
Authors: Farooq Muhammad Sabil , Feroze Nazia , Kai Yuan Tong
Published: October 2019

China’s ‘One Belt One Road’ (OBOR) initiative has been billed as its most ambitious project ever in trying to shape and influence behaviour in the international system in line with her growing stature. At the same time, growing Sino-Africa relations have been the subject of scholarly debate with supporters taking an optimistic view, also presented by China itself, of this relationship being a win-win partnership. Critics led by the United States argue China is just using Africa to extract resources for its use, an allegation it refutes. The authors therefore sought to look at Sino-African relations but focussing on the implementation of OBOR in the African continent. Being the centrepiece of China’s foreign policy since 2013, a study on OBOR in Africa will give an understanding and hopefully answer some questions surrounding these relations. The lack of official bilateral agreements between China and some African countries has been examined, together with the possibility of expansion of the OBOR initiative to cover more African states.
On virtual-force algorithms for coverage-optimal node deployment in mobile sensor networks via the two-dimensional Yukawa crystal
Authors: Tang Rongxin , Qian Xin , Yu Xiangyu
Published: October 2019

As theoretical proof has shown that a hexagonal topology can obtain maximal coverage with a fixed number of sensor nodes, node deployment for mobile sensor networks has the objective of forming a hexagonal network topology while consuming minimum energy. Using virtual-force algorithms to move initially randomly distributed nodes into a target topology is one of the widely studied methods for achieving this goal. In this work, a novel virtual-force algorithm based on physical laws in a dusty plasma system (i.e. VFA-DP) was applied within a mobile sensor network deployment scenario. The VFA-DP force has a central attracting force which can provide a screening effect via exponential decay. Here, to evaluate how perfect the final grids become from virtual-force algorithms, we introduce a performance metric based on the pair correlation function in a crystalline structure. Via simulation studies, we determined that the topology resulting from the VFA-DP is much closer to a hexagon. The analysis also indicated that the VFA-DP converges faster than another virtual-force algorithm based on the Lennard-Jones potential (VFA-LJ), resulting in lower communication-related energy costs in real deployment scenarios. The method developed in this article is derived from studies of crystalline structure from condensed matter physics and shows clear evidence of when the regular lattice is ready. It will provide some guidance for engineering by aiding deployment in complex geometric areas or those recovering from disaster.
Efficient topology control for time-varying spacecraft networks with unreliable links
Authors: Zhang Wei , Ma Hong , Wu Tao , Shi Xueshu , Jiao Yiwen
Published: October 2019

In spacecraft networks, the time-varying topology, intermittent connectivity, and unreliable links make management of the network challenging. Previous works mainly focus on information propagation or routing. However, with a large number of nodes in the future spacecraft networks, it is very crucial regarding how to make efficient network topology controls. In this article, we investigate the topology control problem in spacecraft networks where the time-varying topology can be predicted. We first develop a model that formalizes the time-varying spacecraft network topologies as a directed space–time graph. Compared with most existing static graph models, this model includes both temporal and spatial topology information. To capture the characteristics of practical network, links in our space–time graph model are weighted by cost, efficiency, and unreliability. The purpose of our topology control is to construct a sparse (low total cost) structure from the original topology such that (1) the topology is still connected over space–time graph; (2) the cost efficiency ratio of the topology is minimized; and (3) the unreliability parameter is lower than the required bound. We prove that such an optimization problem is NP-hard. Then, we provide five heuristic algorithms, which can significantly maintain low topology cost efficiency ratio while achieving high reliable connectivity. Finally, simulations have been conducted on random space networks and hybrid low earth orbit/geostationary earth orbit satellite-based sensor network. Simulation results demonstrate the efficiency of our model and topology control algorithms.
Tracking pregnant women displacements in Sao Paulo, Brazil: a complex systems approach to regionalization through the emergence of patterns
Authors: Rigoli Felix , Mascarenhas Sergio , Alves Domingos , Canelas Tiago , Duarte Geraldo
Published: October 2019

Background

The healthcare system can be understood as the dynamic result of the interaction of hospitals, patients, providers, and government configuring a complex network of reciprocal influences. In order to better understand such a complex system, the analysis must include characteristics that are feasible to be studied in order to redesign its functioning. The analysis of the emergent patterns of pregnant women flows crossing municipal borders for birth-related hospitalizations in a region of São Paulo, Brazil, allowed to examine the functionality of the regional division in the state using a complex systems approach and to propose answers to the dilemma of concentration vs. distribution of maternal care regional services in the context of the Brazilian Unified Health System (SUS).

Methods

Cross-sectional research of the areas of influence of hospitals using spatial interaction methods, recording the points of origin and destination of the patients and exploring the emergent patterns of displacement.

Results

The resulting functional region is broader than the limits established in the legal provisions, verifying that 85% of patients move to hospitals with high technology to perform normal deliveries and cesarean sections. The region has high independence rates and behaves as a “service exporter.” Patients going to centrally located hospitals travel twice as long as patients who receive care in other municipalities even when the patients’ conditions do not demand technologically sophisticated services. The effects of regulation and the agents’ preferences reinforce the tendency to refer patients to centrally located hospitals.

Conclusions

Displacement of patients during delivery may affect indicators of maternal and perinatal health. The emergent pattern of movements allowed examining the contradiction between wider deployments of services versus concentration of highly specialized resources in a few places. The study shows the potential of this type of analysis applied to other type of patients’ flows, such as cancer or specialized surgery, as tools to guide the regionalization of the Brazilian Health System.
All-cause mortality in patients with treatment-resistant depression: a cohort study in the US population
Authors: Li Gang , Fife Daniel , Wang Grace , Sheehan John J. , Bodén Robert , Brandt Lena , Brenner Philip , Reutfors Johan , DiBernardo Allitia
Published: October 2019

Background

Treatment-resistant depression (TRD) may represent a substantial proportion of major depressive disorder (MDD); however, the risk of mortality in TRD is still incompletely assessed.

Methods

Data were obtained from Optum Clinformatics™ Extended, a US claims database. Date of the first antidepressant (AD) dispensing was designated as the index date for study entry and 6 months prior to that was considered the baseline period. Patients with MDD aged ≥ 18 years, index date between January 1, 2008 and September 30, 2015, no AD claims during baseline, and continuous enrollment in the database during baseline were included. Patients who started a third AD regimen after two regimens of appropriate duration were included in the TRD cohort. All-cause mortality was compared between patients with TRD and non-TRD MDD using a proportional hazards model and Kaplan–Meier estimate with TRD status being treated as a time-varying covariate. The model was adjusted for study year, age, gender, depression diagnosis, substance use disorder, psychiatric comorbidities, and Charlson comorbidity index.

Results

Out of 355,942 patients with MDD, 34,176 (9.6%) met the criterion for TRD. TRD was associated with a significantly higher mortality compared with non-TRD MDD (adjusted HR: 1.29; 95% CI 1.22–1.38;p < 0.0001). Survival time was significantly shorter in the TRD cohort compared with the non-TRD MDD cohort (p < 0.0001).

Conclusions

Patients with TRD had a higher all-cause mortality compared with non-TRD MDD patients.
Approximations and inequalities for the exponential beta function
Authors: Dragomir Silvestru Sever , Khosrowshahi Farzad
Published: October 2019

In this paper, motivated by interest in simulating the expenditure patterns of construction projects, we introduce the mathematical concept of Exponential-Beta function by$$ F ( \alpha ,\beta ) := \int _{0}^{1}\exp \bigl[ x^{\alpha } ( 1-x ) ^{\beta } \bigr]\,dx, $$F(α,β):=∫01exp[xα(1−x)β]dx,whereα,βare positive numbers. Taylor’s-type approximations, several analytic inequalities, and global convexity properties are established.
Applications of maximum modulus method and Phragmén–Lindelöf method for second-order boundary value problems with respect to the Schrödinger operator
Authors: Liu Zhen
Published: October 2019

In this paper, we present a reliable combination of the maximum modulus method with respect to the Schrödinger operator (Meng in J. Syst. Sci. Complex. 16:446–452, 2003) and Phragmén–Lindelöf method (Shehu in Matematiche 64:57–66, 2015) to investigate the solution of a second-order boundary value problem with respect to the Schrödinger operator. We establish the uniqueness of the solution for this problem. The results reveal that this method is effective and simple.
Serum vascular endothelial growth factor is a biomolecular biomarker of severity of diabetic retinopathy
Authors: Ahuja Sukriti , Saxena Sandeep , Akduman Levent , Meyer Carsten H. , Kruzliak Peter , Khanna Vinay K.
Published: October 2019

Background

Elevated serum vascular endothelial growth factor (VEGF) levels are associated with diabetic retinopathy (DR). Serum VEGF levels correlate with vitreous levels. Neuroretinal changes occur even before the appearance of vascular signs in DR. Role of VEGF as a biomarker for DR has not been assessed. Serum VEGF as a biomarker for severity of DR, was evaluated for the first time.

Methods

Consecutive cases of type 2 diabetes mellitus [without DR, (no DR, n = 38); non-proliferative DR, (NPDR, n = 38); proliferative DR, (PDR, n = 40)] and healthy controls (n = 40) were included. Serum VEGF was measured using enzyme linked immunosorbent assay. Accuracy of VEGF as a biomarker for severity of retinopathy was measured using the area under the receiver operator characteristic (ROC) curve.

Results

Serum VEGF levels in controls, No DR, NPDR and PDR groups showed significant incremental trend from 138.96 ± 63.37 pg/ml (controls) to 457.18 ± 165.69 pg/ml (PDR) (F = 48.47;p < 0.001). Serum VEGF levels were observed to be significantly elevated even before DR had set in clinically. ROC for serum VEGF levels was significant in discriminating between the cases and the controls and had good accuracy in discerning between subjects with and without retinopathy. The area under curve (AUC ± SE) for discrimination was significant: (a) cases and controls (n = 156): AUC = 0.858 ± 0.029,p < 0.001; (b) DR (NPDR + PDR) and No DR (n = 116): AUC = 0.791 ± 0.044,p < 0.001; and (c) NPDR and PDR (n = 78): AUC = 0.761 ± 0.056,p < 0.001, with over 90% projected sensitivity and specificity at various cut off values.

Conclusion

Serum VEGF level is a simple, effective laboratory investigative test in predicting the onset of DR in eyes showing no evidence of DR and serves as a reliable biomolecular biomarker for severity of DR.
Psychiatry and the global drugs debate: what every psychiatrist needs to know
Authors: Bowden-Jones Owen , Sinclair Julia , Lingford-Hughes Anne
Published: October 2019

There are few topics that divide public opinion as sharply as the use of psychoactive substances and it is easy to see why. Substance use is complex and can be examined from numerous perspectives, including legal, health, economic, cultural and ethical. These varying approaches can lead to a range of different conclusions. Here we explore some of the common approaches adopted towards drug policy and suggest a number of principles, which may inform a psychiatrist's own view.
Unemployment Cycles
Authors: Eeckhout Jan , Lindenlaub Ilse
Published: October 2019

The labor market by itself can create cyclical outcomes, even in the absence of exogenous shocks. We propose a theory in which the search behavior of the employed has profound aggregate implications for the unemployed. There is a strategic complementarity between active on-the-job search and vacancy posting by firms, which leads to multiple equilibria: in the presence of sorting, active on-the-job search improves the quality of the pool of searchers. This encourages vacancy posting, which in turn makes costly on-thejob search more attractive—a self-fulfilling equilibrium. The model provides a rationale for the Jobless Recovery, the outward shift of the Beveridge curve during the boom and for pro-cyclical frictional wage dispersion. Central to the model’s mechanism is the fact that the employed crowd out the unemployed when on-the-job search picks up during recovery. We also illustrate this mechanism in a stylized calibration exercise. (JEL E24, E32, J63, J64)
CAPM Condicional: Betas Variantes no Tempo no Mercado Brasileiro
Authors: Blank Frances Fischberg , Samanez Carlos Patricio , Baidya Tara Keshar Nanda , Aiube Fernando Antonio Lucena
Published: October 2019

O CAPM condicional pressupõe a variação temporal do beta de mercado. À luz de modelos espaço-estado, a dinâmica de beta pode ser modelada como um processo estocástico combinado com variáveis condicionantes relativas ao ciclo econômico e estimada através do filtro de Kalman. Este artigo analisa modelagens alternativas no que se refere ao ajuste aos dados de carteiras ordenadas por valor de mercado e razão book-to-market no mercado brasileiro, bem como à capacidade de explicação dos erros de apreçamento em relação ao CAPM incondicional através de testes sob abordagens de séries temporais e cross-sectional. O modelo em que beta segue passeio aleatório combinado com variáveis condicionantes é o que apresenta melhor resultado ao reduzir erros de apreçamento, mas, apesar da redução, estes permanecem ainda significativos. Testes cross-sectional indicam que a variável book-to-market perde poder na explicação dos retornos, mas evidenciam uma influência de variável relativa a retornos passados.
Indexação de Fundos de Pensão com Fundos de Índice
Authors: Sanfins Maria Alcina Rodrigues Batista , Duarte Júnior Antonio Marcos
Published: October 2019

Este artigo considera o uso de Fundos de Índice (FI) para a indexação das carteiras de fundos de pensão no Brasil. Uma metodologia é apresentada para a utilização combinada de FI e dos ativos que compõem o índice de referência escolhido. A metodologia está baseada em modelos de programação matemática, com os problemas resultantes resolvidos numericamente com qualquer algoritmo de otimização global. A modelagem é ilustrada para o caso do mercado acionário brasileiro com estudos simulados para dois FI: BOVA11 (indexado ao Ibovespa) e BRAX11 (indexado ao IBrX-100). As limitações impostas pela legislação em vigor foram incorporadas aos estudos simulados. A metodologia se provou uma alternativa eficiente para os gestores de fundos de pensão, com bons resultados no que se refere ao controle do erro de aderência.
A importância do relacionamento bancário no financiamento das PME: estudo numa agência bancária portuguesa
Authors: Silva Armando Mendes Jorge Nogueira da , Braga Silvia Maria Graça
Published: October 2019

Tendo como ponto de partida uma amostra de pequenas e médias empresas portuguesas clientes de crédito de uma dada agência bancária, examina-se empiricamente o papel do relacionamento bancário e da situação económico-financeira na determinação das condições de financiamento obtidas pelas mesmas. Tendo por base uma análise de regressão múltipla, verificou-se que, para no modelo explicativo do nível de prémio de risco as únicas variáveis que revelaram importância para a explicação do mesmo foram a reputação, o montante de crédito concedido e a liquidez geral do cliente. Relativamente ao modelo explicativo do montante de crédito concedido, a variável duração tem um impacto significativo, indicando que os relacionamentos são valiosos. Em ambos os modelos, as variáveis que demonstraram ter um maior impacto no montante de crédito disponibilizado foram variáveis relacionadas com a performance económico-financeira das empresas da amostra.
Excesso de confiança, turnover e retorno: evidência no mercado brasileiro
Authors: Prates Wlademir Ribeiro , Santos André Alves Portela , Costa Jr. Newton Carneiro Affonso da
Published: October 2019

A literatura de finanças tem apresentado evidências de uma relação positiva entre o volume negociado e as variações nos preços das ações. Esta relação pode ser explicada pelo conceito de excesso de confiança, dentro das finanças comportamentais, o qual postula que quando retornos positivos ocorrem, o investidor tende a realizar mais operações, movido pelo excesso de confiança presente no mercado. Este trabalho procurou analisar como ocorre a relação (tanto passada quanto contemporânea) entre retorno e volume (medido pelo turnover) baseado na metodologia de Statman et al. (2006). Foram analisadas todas as ações negociadas na BM&FBovespa para o período de janeiro de 1995 até dezembro de 2012. O principal resultado deste artigo enfatiza a existência de uma relação positiva entre turnover e retorno (tanto passado quanto contemporâneo) apenas para as ações com baixo valor de mercado.
Ganhos econômicos da volatilidade realizada no mercado Brasileiro de ações
Authors: Garcia Márcio Gomes Pinto , Medeiros Marcelo Cunha , Santos Francisco Eduardo de Luna e Almeida
Published: October 2019

O artigo avalia os ganhos econômicos associados à execução de uma estratégia baseada em volatilidade a partir de um modelo multivariado de volatilidade realizada. Para tanto, construímos uma base de dados em alta frequência que contém as ações mais negociadas no mercado de ações Brasileiro. A comparação com modelos tradicionais de volatilidade mostra que, quando o risco de estimação é controlado, há ganhos econômicos positivos associados às medidas de volatilidade realizada e tais ganhos crescem proporcionalmente aos retornos-alvo. No entanto, quando os retornos esperados são randomizados, as taxas de desempenho não são significativas, sugerindo que os ganhos econômicos da volatilidade realizada são compensados pelo risco de estimação.
Teoria de Medidas de Risco: uma revisão abrangente
Authors: Righi Marcelo Brutti , Ceretta Paulo Sergio
Published: October 2019

Um aspecto fundamental de uma correta gestão de risco é a mensuração, especialmente a previsão de medidas de risco. Inicialmente se considerava medidas de risco, como variância, volatilidade e Valor em Risco, como sendo válidas por sua intuição prática. Todavia, um sólido arcabouço teórico se fez necessário para garantir melhores propriedades para medidas de risco. Esse aporte é a teoria de medidas de risco. O presente trabalho apresenta uma revisão de literatura abrangente sobre teoria de medidas de risco, focando teoria básica e em extensões à essa estrutura fundamental. A apresentação é focada nas principais classes de medidas de risco da literatura, que são medidas de risco coerentes, medidas de risco convexas, medidas de risco espectrais e de distorção e medidas de desvio generalizado.
Estrutura Piramidal de Controle, Emissão de Duas Classes de Ações e Desempenho Financeiro das Empresas Brasileiras
Authors: Andrade Lelis Pedro , Bressan Aureliano Angel , Iquiapaza Robert Aldo
Published: October 2019

Objetivou-se neste trabalho identificar se existe relação entre a emissão de duas classes de ações, a existência de estrutura piramidal de controle e o desempenho financeiro das empresas brasileiras. Para tanto, utilizaram-se testes univariados e modelos de dados em painel para um período amostral entre 2000 a 2012. Os resultados indicam que é negativa a influência que a emissão de duas classes de ações exerce sobre o desempenho financeiro, independente do fato de a empresa possuir ou não estrutura piramidal. Já a estrutura piramidal de controle exerce um efeito positivo, desde que a empresa não possua ações sem direito a voto, e que não seja elevada a quantidade de camadas existentes até o último nível da estrutura. Estes resultados sugerem que a concessão do poder de voto e a estrutura piramidal de controle com um número reduzido de camadas são fatores relevantes que influenciam positivamente o desempenho financeiro das empresas brasileiras de capital aberto.
Teste da Hipótese de Mercados Adaptativos para o Brasil
Authors: Dourado Glener de Almeida , Tabak Benjamin Miranda
Published: October 2019

O objetivo deste trabalho é o de avaliar a eficiência do mercado acionário brasileiro utilizando dados diários para o Índice Acionário da Bolsa de São Paulo, no período de janeiro de 1995 a dezembro de 2012. Empregamos uma estatística de razão de variância com wild bootstrap, desenvolvido para testar a dependência linear (Hipótese de Passeio Aleatório – HPA). Também usamos o teste espectral generalizado para testar a hipótese de previsibilidade não linear. Empregamos o teste de razão de variâncias usando subamostras com tamanho fixo, verificando a existência de comportamento de passeio aleatório em cada subamostra. Ainda, testamos se a eficiência do mercado depende das condições de mercado (Adaptative Markets Hypothesis – AMH). As conclusões sugerem que não podemos rejeitar tanto a HPA quanto a AMH.