bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lyness cycles
Authors: Dolan Stan 
Published: June 2017

In 1942, R. C. Lyness noted that some recurrence relations generate cycles, irrespective of the initial values. For example, the order 2 recurrence relationgenerates a cycle of period 5 for almost all values of u1 and u2 [1].The globally periodic nature of sequences generated by this recurrence relation can be seen by setting u1 = x and u2 = y. The sequence is thenLyness gave other examples of such recurrence relations but had been unable to find one with period 7 and challenged readers of the Gazette to find such a recurrence relation or prove it to be impossible.No answer to this challenge was forthcoming. However, since Lyness's time, interest in these cycles has been maintained due to links with cross-ratios and elliptic curves. In recent years, Jonny Griffiths has done much to popularise these cycles [2].
Properties of bisect-diagonal quadrilaterals
Authors: Josefsson Martin 
Published: June 2017

The general class of quadrilaterals where one diagonal is bisected by the other diagonal has appeared very rarely in the geometrical literature, but they have been named several times in connection with quadrilateral classifications. Günter Graumann strangely gave these objects two different names in [1, pp. 192, 194]: sloping-kite and sliding-kite. A. Ramachandran called them slant kites in [2, p. 54] and Michael de Villiers called them bisecting quadrilaterals in [3, pp. 19, 206]. The latter is a pretty good name, although a bit confusing: what exactly is bisected?We have found no papers and only two books where any theorems on such quadrilaterals are studied. In each of the books, one necessary and sufficient condition for such quadrilaterals is proved (see Theorem 1 and 2 in the next section). The purpose of this paper is to investigate basic properties of convex bisecting quadrilaterals, but we have chosen to give them a slightly different name. Let us first remind the reader that a quadrilateral whose diagonals have equal lengths is called an equidiagonal quadrilateral and one whose diagonals are perpendicular is called an orthodiagonal quadrilateral.
Finding sums of powers using physical arguments
Authors: Treeby David 
Published: June 2017

In an earlier issue of the Mathematical Gazette, Nick Lord established the familiar formula for the sum of the first n squares using a physical argument based on the centroid of a configuration of masses in the plane [1]. In [2] we demonstrate an alternative configuration that gives the same result. This article is a follow-up to these papers, in which we find physical derivations of the formula forfor each k ∈ {1, 2, 3, 4, 5}. Let us first summarise the required theory. Take any region X ⊆ ℝ2 with uniform density and total area A. The centroid of is the arithmetic mean position of all of the points in X. If a region has a line of symmetry then the centroid will be located on that line.
Stratigraphic and palaeoecological evidence for late medieval to early modern peat extraction from bogs in Het Gooi (Western Netherlands)
Authors: Sevink Jan , van Geel Bas 
Published: June 2017

AbstractIn the Monnikenberg estate, built in the mid-19th century in a Pleistocene coversand area to the south of Hilversum (the Netherlands), a depression with a small man-made mire was found to contain the remains of a complex peaty fill of a larger mire. Microfossil study and radiocarbon dating showed that its development started at the beginning of the third millennium BC through water stagnation on a podzol in combination with a high groundwater level, and about two millennia ago the vegetation had progressed from a mesotrophic mire to an ombrotrophic bog. Such origin, development and age are in conformity with the results for some other recently studied mires in the Het Gooi region (Gijzenveen; Van Geel et al., 2016). In the Monnikenberg mire, a discrepancy was found between the radiocarbon age of the upper part of the peaty fill and its clearly medieval or younger age as evidenced by its microfossil content, notably the occurrence of pollen of buckwheat (Fagopyrum) and cornflower (Centaurea cyanus). These species were first introduced in the Netherlands during the late Middle Ages. From further observations in a large pit in the former border zone of the mire, it is concluded that this discrepancy and the unique sedimentary structures, observed in this pit, result from peat exploitation and contemporary reworking of its sandy overburden during the Late Middle Ages or Early Modern Times. This is the first evidence for local early peat exploitation for such mires in Het Gooi. The results underpin the importance of microfossil analyses for proper interpretation of radiocarbon data, when studying mire fills. Additionally, they provide further proof for the development of podzols and ericaceous vegetation prior to and independent of early prehistoric agriculture in the Dutch Pleistocene coversand areas, and for the early (pre-medieval) start of wind erosion and deposition of drift sands.
No perceptual reorganization for Limburgian tones? A cross-linguistic investigation with 6- to 12-month-old infants
Authors: RAMACHERS STEFANIE , BROUWER SUSANNE , FIKKERT PAULA 
Published: June 2017

AbstractDespite the fact that many of the world's languages use lexical tone, the majority of language acquisition studies has focused on non-tone languages. Research on tone languages has typically investigated well-known tone languages such as Mandarin and Cantonese Chinese. The current study looked at a Limburgian dialect of Dutch that uses lexical pitch differences, albeit in a rather restricted way. Using a visual habituation paradigm, 6- to 12-month-old Limburgian and Dutch infants were tested for their ability to discriminate Limburgian tones. The results showed that both Limburgian and Dutch infants discriminate the Limburgian tones throughout their first year of life. The role of linguistic experience, acoustic salience, and the degree of similarity to the native prosodic system are discussed.
Parkinson’s Disease Subtypes Show Distinct Tradeoffs Between Response Initiation and Inhibition Latencies
Authors: Tolleson Christopher , Turchan Maxim , van Wouwe Nelleke , Isaacs David , Phibbs Fenna , Wylie Scott 
Published: June 2017

AbstractObjectives: In unpredictable situations, individuals often show tradeoffs between response initiation and inhibition speeds. We tested the hypothesis that Parkinson’s disease (PD) motor subtypes differentially impact tradeoffs between these two action-oriented processes. We predicted that, compared to tremor dominant (TD) patients, predominant postural instability and gait dysfunction (PIGD) patients would show exacerbated tradeoffs between response initiation and inhibition in situations requiring the sudden potential need to interrupt an action. Methods: Fifty-one PD patients (subdivided into PIGD [n=27] and TD [n=24]) and 21 healthy controls (HCs) completed a choice reaction task to establish baseline response initiation speed between groups. Subsequently, participants completed a stop-signal task which introduced an occasional, unpredictable stop stimulus. We measured changes in initiation speed in preparation of an unpredictable stop (i.e., proactive slowing) and inhibition latency (i.e., stop-signal reaction time). Results: Compared to HCs, PD patients showed slower response initiation speeds in the choice reaction task. All groups showed proactive slowing in the stop-signal task but the magnitude was considerably larger in PIGD patients, almost twice as large as TD patients. PD patients, irrespective of motor subtype, showed longer inhibition latencies than HCs. Conclusions: PIGD and TD subtypes both showed exacerbated response inhibition deficits. However, PIGD patients showed much more pronounced proactive slowing in situations with an expected yet unpredictable need to stop action abruptly. This suggests that PIGD is accompanied by exaggerated tradeoffs between response initiation and inhibition processes to meet situational action demands. We discuss putative neural mechanisms and clinical implications of these findings. (JINS, 2017, 23, 665–674)
Damming and Infrastructural Development of the Indus River Basin: Strengthening the Provisions of the Indus Waters Treaty
Authors: RAMAN Durgeshree 
Published: June 2017

AbstractWhilst the Indus Waters Treaty of 1960 allows for damning and infrastructural development in the Indus River Basin, it does so without factoring in environmental considerations. This is because environmental standards in international law, except those related to pollution control, were largely absent when the Treaty was negotiated in the 1950s. Given the increasing list of development-related disputes between India and Pakistan, and their aspirations for further damming and other infrastructural works in the Basin, this paper seeks to close the gaps in the Treaty’s provisions and developments in international environmental law to date. To do so effectively, the paper analyzes the relevant provisions of the UN Watercourses Convention, supplemented with an examination of the European regional framework. Based on these, it proposes changes to the Treaty so that both India and Pakistan are able to work within a legal framework which not only provides for environmental impact assessments for planned projects, but enhances monitoring, assessments, and reporting. This will ensure that such developments are not only environmentally sound but also help to alleviate some of the disputes between India and Pakistan.
Interaction between autophagy and senescence is required for dihydroartemisinin to alleviate liver fibrosis
Authors: Zhang Zili , Yao Zhen , Zhao Shifeng , Shao Jiangjuan , Chen Anping , Zhang Feng , Zheng Shizhong 
Published: June 2017

AbstractAutophagy and cellular senescence are stress responses essential for homeostasis. Therefore, they may represent new pharmacologic targets for drug development to treat diseases. In this study, we sought to evaluate the effect of dihydroartemisinin (DHA) on senescence of activated hepatic stellate cells (HSCs), and to further elucidate the underlying mechanisms. We found that DHA treatment induced the accumulation of senescent activated HSCs in rat fibrotic liver, and promoted the expression of senescence markers p53, p16, p21 and Hmga1 in cell model. Importantly, our study identified the transcription factor GATA6 as an upstream molecule in the facilitation of DHA-induced HSC senescence. GATA6 accumulation promoted DHA-induced p53 and p16 upregulation, and contributed to HSC senescence. By contrast, siRNA-mediated knockdown of GATA6 dramatically abolished DHA-induced upregulation of p53 and p16, and in turn inhibited HSC senescence. Interestingly, DHA also appeared to increase autophagosome generation and autophagic flux in activated HSCs, which was underlying mechanism for DHA-induced GATA6 accumulation. Autophagy depletion impaired GATA6 accumulation, while autophagy induction showed a synergistic effect with DHA. Attractively, p62 was found to act as a negative regulator of GATA6 accumulation. Treatment of cultured HSCs with various autophagy inhibitors, led to an inhibition of DHA-induced p62 degradation, and in turn, prevented DHA-induced GATA6 accumulation and HSC senescence. Overall, these results provide novel implications to reveal the molecular mechanism of DHA-induced senescence, by which points to the possibility of using DHA based proautophagic drugs for the treatment of liver fibrosis.
Heme oxygenase-1 derived carbon monoxide suppresses Aβ1–42 toxicity in astrocytes
Authors: Hettiarachchi Nishani T , Boyle John P , Dallas Mark L , Al-Owais Moza M , Scragg Jason L , Peers Chris 
Published: June 2017

AbstractNeurodegeneration in Alzheimer’s disease (AD) is extensively studied, and the involvement of astrocytes and other cell types in this process has been described. However, the responses of astrocytes themselves to amyloid β peptides ((Aβ; the widely accepted major toxic factor in AD) is less well understood. Here, we show that Aβ
(1-42)
is toxic to primary cultures of astrocytes. Toxicity does not involve disruption of astrocyte Ca
2+
homeostasis, but instead occurs via formation of the toxic reactive species, peroxynitrite. Thus, Aβ
(1-42)
raises peroxynitrite levels in astrocytes, and Aβ
(1-42)
toxicity can be inhibited by antioxidants, or by inhibition of nitric oxide (NO) formation (reactive oxygen species (ROS) and NO combine to form peroxynitrite), or by a scavenger of peroxynitrite. Increased ROS levels observed following Aβ
(1-42)
application were derived from NADPH oxidase. Induction of haem oxygenase-1 (HO-1) protected astrocytes from Aβ
(1-42)
toxicity, and this protective effect was mimicked by application of the carbon monoxide (CO) releasing molecule CORM-2, suggesting HO-1 protection was attributable to its formation of CO. CO suppressed the rise of NADPH oxidase-derived ROS caused by Aβ
(1-42)
. Under hypoxic conditions (0.5% O
2
, 48 h) HO-1 was induced in astrocytes and Aβ
(1-42)
toxicity was significantly reduced, an effect which was reversed by the specific HO-1 inhibitor, QC-15. Our data suggest that Aβ
(1-42)
is toxic to astrocytes, but that induction of HO-1 affords protection against this toxicity due to formation of CO. HO-1 induction, or CO donors, would appear to present attractive possible approaches to provide protection of both neuronal and non-neuronal cell types from the degenerative effects of AD in the central nervous system.
RETRACTED ARTICLE:LISPRO mitigates β-amyloid and associated pathologies in Alzheimer’s mice
Authors: Habib Ahsan , Sawmiller Darrell , Li Song , Xiang Yang , Rongo David , Tian Jun , Hou Huayan , Zeng Jin , Smith Adam , Fan Shengnuo , Giunta Brian , Mori Takashi , Currier Glenn , Shytle Douglas Ronald , Tan Jun 
Published: June 2017

AbstractLithium has been marketed in the United States of America since the 1970s as a treatment for bipolar disorder. More recently, studies have shown that lithium can improve cognitive decline associated with Alzheimer’s disease (AD). However, the current United States Food and Drug Administration-approved lithium pharmaceutics (carbonate and citrate chemical forms) have a narrow therapeutic window and unstable pharmacokinetics that, without careful monitoring, can cause serious adverse effects. Here, we investigated the safety profile, pharmacokinetics, and therapeutic efficacy of LISPRO (ionic co-crystal of lithium salicylate and l-proline), lithium salicylate, and lithium carbonate (Li2CO3). We found that LISPRO (8-week oral treatment) reduces β-amyloid plaques and phosphorylation of tau by reducing neuroinflammation and inactivating glycogen synthase kinase 3β in transgenic Tg2576 mice. Specifically, cytokine profiles from the brain, plasma, and splenocytes suggested that 8-week oral treatment with LISPRO downregulates pro-inflammatory cytokines, upregulates anti-inflammatory cytokines, and suppresses renal cyclooxygenase 2 expression in transgenic Tg2576 mice. Pharmacokinetic studies indicated that LISPRO provides significantly higher brain lithium levels and more steady plasma lithium levels in both B6129SF2/J (2-week oral treatment) and transgenic Tg2576 (8-week oral treatment) mice compared with Li2CO3. Oral administration of LISPRO for 28 weeks significantly reduced β-amyloid plaques and tau-phosphorylation. In addition, LISPRO significantly elevated pre-synaptic (synaptophysin) and post-synaptic protein (post synaptic density protein 95) expression in brains from transgenic 3XTg-AD mice. Taken together, our data suggest that LISPRO may be a superior form of lithium with improved safety and efficacy as a potential new disease modifying drug for AD.
Water scarcity hotspots travel downstream due to human interventions in the 20th and 21st century
Authors: Veldkamp T.I.E. , Wada Y. , Aerts J.C.J.H. , Döll P. , Gosling S. N. , Liu J. , Masaki Y. , Oki T. , Ostberg S. , Pokhrel Y. , Satoh Y. , Kim H. , Ward P. J. 
Published: June 2017

AbstractWater scarcity is rapidly increasing in many regions. In a novel, multi-model assessment, we examine how human interventions (HI: land use and land cover change, man-made reservoirs and human water use) affected monthly river water availability and water scarcity over the period 1971–2010. Here we show that HI drastically change the critical dimensions of water scarcity, aggravating water scarcity for 8.8% (7.4–16.5%) of the global population but alleviating it for another 8.3% (6.4–15.8%). Positive impacts of HI mostly occur upstream, whereas HI aggravate water scarcity downstream; HI cause water scarcity to travel downstream. Attribution of water scarcity changes to HI components is complex and varies among the hydrological models. Seasonal variation in impacts and dominant HI components is also substantial. A thorough consideration of the spatially and temporally varying interactions among HI components and of uncertainties is therefore crucial for the success of water scarcity adaptation by HI.
Tidal dynamics and mangrove carbon sequestration during the Oligo–Miocene in the South China Sea
Authors: Collins Daniel S. , Avdis Alexandros , Allison Peter A. , Johnson Howard D. , Hill Jon , Piggott Matthew D. , Hassan Meor H. Amir , Damit Abdul Razak 
Published: June 2017

AbstractModern mangroves are among the most carbon-rich biomes on Earth, but their long-term (≥106 years) impact on the global carbon cycle is unknown. The extent, productivity and preservation of mangroves are controlled by the interplay of tectonics, global sea level and sedimentation, including tide, wave and fluvial processes. The impact of these processes on mangrove-bearing successions in the Oligo–Miocene of the South China Sea (SCS) is evaluated herein. Palaeogeographic reconstructions, palaeotidal modelling and facies analysis suggest that elevated tidal range and bed shear stress optimized mangrove development along tide-influenced tropical coastlines. Preservation of mangrove organic carbon (OC) was promoted by high tectonic subsidence and fluvial sediment supply. Lithospheric storage of OC in peripheral SCS basins potentially exceeded 4,000 Gt (equivalent to 2,000 p.p.m. of atmospheric CO2). These results highlight the crucial impact of tectonic and oceanographic processes on mangrove OC sequestration within the global carbon cycle on geological timescales.
Terahertz saturable absorbers from liquid phase exfoliation of graphite
Authors: Bianchi Vezio , Carey Tian , Viti Leonardo , Li Lianhe , Linfield Edmund H. , Davies A. Giles , Tredicucci Alessandro , Yoon Duhee , Karagiannidis Panagiotis G. , Lombardi Lucia , Tomarchio Flavia , Ferrari Andrea C. , Torrisi Felice , Vitiello Miriam S. 
Published: June 2017

AbstractSaturable absorbers (SA) operating at terahertz (THz) frequencies can open new frontiers in the development of passively mode-locked THz micro-sources. Here we report the fabrication of THz SAs by transfer coating and inkjet printing single and few-layer graphene films prepared by liquid phase exfoliation of graphite. Open-aperture z-scan measurements with a 3.5 THz quantum cascade laser show a transparency modulation ∼80%, almost one order of magnitude larger than that reported to date at THz frequencies. Fourier-transform infrared spectroscopy provides evidence of intraband-controlled absorption bleaching. These results pave the way to the integration of graphene-based SA with electrically pumped THz semiconductor micro-sources, with prospects for applications where excitation of specific transitions on short time scales is essential, such as time-of-flight tomography, coherent manipulation of quantum systems, time-resolved spectroscopy of gases, complex molecules and cold samples and ultra-high speed communications, providing unprecedented compactness and resolution.
Cryptic indole hydroxylation by a non-canonical terpenoid cyclase parallels bacterial xenobiotic detoxification
Authors: Kugel Susann , Baunach Martin , Baer Philipp , Ishida-Ito Mie , Sundaram Srividhya , Xu Zhongli , Groll Michael , Hertweck Christian 
Published: June 2017

AbstractTerpenoid natural products comprise a wide range of molecular architectures that typically result from C–C bond formations catalysed by classical type I/II terpene cyclases. However, the molecular diversity of biologically active terpenoids is substantially increased by fully unrelated, non-canonical terpenoid cyclases. Their evolutionary origin has remained enigmatic. Here we report thein vitroreconstitution of an unusual flavin-dependent bacterial indoloterpenoid cyclase, XiaF, together with a designated flavoenzyme-reductase (XiaP) that mediates a key step in xiamycin biosynthesis. The crystal structure of XiaF with bound FADH2(at 2.4 Å resolution) and phylogenetic analyses reveal that XiaF is, surprisingly, most closely related to xenobiotic-degrading enzymes. Biotransformation assays show that XiaF is a designated indole hydroxylase that can be used for the production of indigo and indirubin. We unveil a cryptic hydroxylation step that sets the basis for terpenoid cyclization and suggest that the cyclase has evolved from xenobiotics detoxification enzymes.
The genomic landscape of tuberous sclerosis complex
Authors: Martin Katie R. , Zhou Wanding , Bowman Megan J. , Shih Juliann , Au Kit Sing , Dittenhafer-Reed Kristin E. , Sisson Kellie A. , Koeman Julie , Weisenberger Daniel J. , Cottingham Sandra L. , DeRoos Steven T. , Devinsky Orrin , Winn Mary E. , Cherniack Andrew D. , Shen Hui , Northrup Hope , Krueger Darcy A. , MacKeigan Jeffrey P. 
Published: June 2017

AbstractTuberous sclerosis complex (TSC) is a rare genetic disease causing multisystem growth of benign tumours and other hamartomatous lesions, which leads to diverse and debilitating clinical symptoms. Patients are born with TSC1 or TSC2 mutations, and somatic inactivation of wild-type alleles drives MTOR activation; however, second hits to TSC1/TSC2 are not always observed. Here, we present the genomic landscape of TSC hamartomas. We determine that TSC lesions contain a low somatic mutational burden relative to carcinomas, a subset feature large-scale chromosomal aberrations, and highly conserved molecular signatures for each type exist. Analysis of the molecular signatures coupled with computational approaches reveals unique aspects of cellular heterogeneity and cell origin. Using immune data sets, we identify significant neuroinflammation in TSC-associated brain tumours. Taken together, this molecular catalogue of TSC serves as a resource into the origin of these hamartomas and provides a framework that unifies genomic and transcriptomic dimensions for complex tumours.
Insufficient antibody validation challenges oestrogen receptor beta research
Authors: Andersson Sandra , Sundberg Mårten , Pristovsek Nusa , Ibrahim Ahmed , Jonsson Philip , Katona Borbala , Clausson Carl-Magnus , Zieba Agata , Ramström Margareta , Söderberg Ola , Williams Cecilia , Asplund Anna 
Published: June 2017

AbstractThe discovery of oestrogen receptor β (ERβ/ESR2) was a landmark discovery. Its reported expression and homology with breast cancer pharmacological target ERα (ESR1) raised hopes for improved endocrine therapies. After 20 years of intense research, this has not materialized. We here perform a rigorous validation of 13 anti-ERβ antibodies, using well-characterized controls and a panel of validation methods. We conclude that only one antibody, the rarely used monoclonal PPZ0506, specifically targets ERβ in immunohistochemistry. Applying this antibody for protein expression profiling in 44 normal and 21 malignant human tissues, we detect ERβ protein in testis, ovary, lymphoid cells, granulosa cell tumours, and a subset of malignant melanoma and thyroid cancers. We do not find evidence of expression in normal or cancerous human breast. This expression pattern aligns well with RNA-seq data, but contradicts a multitude of studies. Our study highlights how inadequately validated antibodies can lead an exciting field astray.