bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metaplastic Reinforcement of Long-Term Potentiation in Hippocampal Area CA2 by Cholinergic Receptor Activation
Authors: Benoy Amrita , Bin Ibrahim Mohammad Zaki , Behnisch Thomas , Sajikumar Sreedharan 
Published: September 2021

Hippocampal CA2, an inconspicuously positioned area between the well-studied CA1 and CA3 subfields, has captured research interest in recent years because of its role in social memory formation. However, the role of cholinergic inputs to the CA2 area for the regulation of synaptic plasticity remains to be fully understood. We show that cholinergic receptor activation with the nonselective cholinergic agonist, carbachol (CCh), triggers a protein synthesis-dependent and NMDAR-independent long-term synaptic depression (CCh-LTD) at entorhinal cortical (EC)-CA2 and Schaffer collateral (SC)-CA2 synapses in the hippocampus of adult male Wistar rats. The activation of muscarinic acetylcholine receptors (mAChRs) is critical for the induction of CCh-LTD with the results suggesting an involvement of M3 and M1 mAChRs in the early facilitation of CCh-LTD, while nicotinic AChR activation plays a role in the late maintenance of CCh-LTD at CA2 synapses. Remarkably, we find that CCh priming lowers the threshold for the subsequent induction of persistent long-term potentiation (LTP) of synaptic transmission at EC-CA2 and the plasticity-resistant SC-CA2 pathways. The effects of such a cholinergic-dependent synaptic depression on subsequent LTP at EC-CA2 and SC-CA2 synapses have not been previously explored. Collectively, the results demonstrate that CA2 synaptic learning rules are regulated in a metaplastic manner, whereby modifications triggered by prior cholinergic stimulation can dictate the outcome of future plasticity events. Moreover, the reinforcement of LTP at EC inputs to CA2 following the priming stimulus coexists with concurrent sustained CCh-LTD at the SC-CA2 pathway and is dynamically scaled by modulation of SC-CA2 synaptic transmission.SIGNIFICANCE STATEMENTThe release of the neuromodulator acetylcholine is critically involved in processes of hippocampus-dependent memory formation. Cholinergic afferents originating in the medial septum and diagonal bands of Broca terminating in the hippocampal area CA2 might play an important role in the modulation of area-specific synaptic plasticity. Our findings demonstrate that cholinergic receptor activation induces an LTD of synaptic transmission at entorhinal cortical- and Schaffer collateral-CA2 synapses. This cholinergic activation-mediated LTD displays a bidirectional metaplastic switch to LTP on a future timescale. This suggests that such bidirectional synaptic modifications triggered by the dynamic modulation of tonic cholinergic receptor activation may support the formation of CA2-dependent memories given the increased hippocampal cholinergic tone during active wakefulness observed in exploratory behavior.
Turizmde sürdürülebilirlik göstergeleri: Otel işletmeleri yöneticileri üzerine bir uygulama
Authors: Tamer Elif Tuba , Mısırdalı Yangil Fulya 
Published: September 2021

Bu çalışmanın amacı otel işletmeleri yöneticilerinin sürdürülebilir turizme bakış açılarının incelenerek otel işletmelerindeki sürdürülebilirlik algısının tespit edilmesidir. Çalışmanın verileri sosyal, ekonomik, çevresel, kültürel, politik ve teknolojik sürdürülebilirlik boyutlarını ve bu boyutların alt bileşenlerini içeren ikili karşılaştırmalar şeklinde hazırlanan bir anket çalışmasıyla elde edilmiştir. Elde edilen veriler çok kriterli karar verme yöntemlerinden Analitik Hiyerarşi Süreci (AHP) yöntemi ile analiz edilmiştir. Çalışmada Bodrum’da faaliyette bulunan beş yıldızlı otel işletmelerindeki yöneticilerden elde edilen verilerin analizi sonucunda, yöneticilerin algılarına göre öncelik sırası en yüksek boyutun çevresel sürdürülebilirlik olduğu tespit edilmiştir. Diğer sürdürülebilirlik boyutları da sırasıyla, ekonomik, kültürel, teknolojik, politik ve sosyal sürdürülebilirlik olduğu sonucuna ulaşılmıştır. Bu çalışma önemli bir paydaş grubu olan otel işletmelerinin sürdürülebilirlik algılarının tespit edilmesi ve sürdürülebilirlik boyutlarının önceliklendirmesi açısından yol gösterici bir çalışma olmaktadır. Çalışma bulgularına göre, birçok alanda olduğu gibi turizm alanında da sürdürülebilirlik, genel olarak çevresel sürdürülebilirlik bağlamında ele alınmaktadır. Bu durum turizmin çevreyle olan karşılıklı ilişkisinin bir sonucudur.
Diagnostic performance of the calcium/phosphate ratio for primary hyperparathyroidism in southwest China
Authors: Yin Mengting , Liu Qianhui , Wang Qingzhong , He Yong , Song Haolan , Nie Xin , Li Guixing 
Published: September 2021

Background
The diagnosis of primary hyperparathyroidism (PHPT) remains a challenge because of increased asymptomatic PHPT or patients with normocalcaemic PHPT (NPHPT). In addition, some primary hospitals in China have no equipment to measure parathyroid hormone (PTH) levels. Therefore, an additional, simple, and inexpensive laboratory biochemical marker is urgently needed. The calcium/phosphate (Ca/P) ratio and chloride/phosphate (Cl/P) ratio have been proposed as suitable tools to diagnose PHPT in Europe; however, the Ca/P ratio has never been tested in China. We aimed to conduct a confirmatory study to explore the diagnostic performance of the Ca/P ratio for PHPT in China.

Methods
From January 2015 to December 2020, a total of 155 patients who underwent parathyroidectomy (143 PHPT patients and 12 NPHPT patients) and 153 controls were enrolled in this single-center , retrospective study. Serum calcium, phosphate, parathyroid hormone, 25-hydroxyvitamin vitamin D (25(OH) vitamin D), chloride, alanine transaminase (ALT), aspartate aminotransaminase (AST), estimated glomerular filtration rate (eGFR), and creatinine levels were recorded for all the study participants. Pairwise comparisons were made between groups, and the diagnostic performance of the Ca/P ratio was determined using receiver-operating characteristic (ROC) analysis.

Results
Patients with PHPT had a higher Ca/P ratio than controls (P < 0.001). A Ca/P ratio above 2.94 with a sensitivity of 95.5% and specificity of 98.7% can distinguish PHPT patients from healthy individuals. This index was positively correlated with the PTH level (r = 0.875, P < 0.001).

Conclusion
The Ca/P ratio is an ideal and inexpensive indicator for diagnosing PHPT in China when using a cut-off value of 2.94.
Desarrollo urbano y ciudades (in) sustentables: retos para la convivencia
Authors: Leme Garcez María Cecilia 
Published: September 2021

El cuidado social y los espacios de convivencia saludable son características imprescindibles para un desarrollo urbano justo y equitativo en las grandes ciudades. El objetivo de este estudio es realizar una aproximación teórica y analítica al desarrollo urbano en América Latina, y presentar algunas perspectivas críticas de los modelos de desarrollo que se restringen a metas de crecimiento económico, lo que vuelve inviable una convivencia saludable en las grandes ciudades, entre las personas y con el medioambiente. Metodológicamente, el estudio asume el enfoque cualitativo, de carácter bibliográfico, documental y social.
Kadın Giyim Modasında Siyah Renk Kullanımı
Authors: DEMİR PARLAK Sevda , ÖNLÜ Nesrin 
Published: September 2021

Günümüz moda oluşumlarında hızlı değişimler yaşanmaktadır. İnsanların dinamik yapılarından kaynaklanan sürekli değişim, tasarımcıları yeni arayışlara itmekte, dolayısıyla moda ve rengi oluşturan öğeler kendilerini yenilemek durumunda kalmaktadır. İnsan beğenisini şekillendiren en önemli ögelerden biri olan renk, tasarımcı ile kullanıcı arasındaki köprüyü doğrudan kurarak psikolojik algılamayı harekete geçirmektedir.
Sözsüz iletişim aracı olan giyimin, karşı tarafa iletmek istediği mesajı renk belirlemektedir. Renklerin anlamı tarihsel süreçte ve farklı kültürlerde yaşandığı dönemlere göre farklılık gösterirken, siyah renk kalıcı geniş bir anlam aralığına sahip olmuştur. Bu çalışma olumlu ve olumsuz, geniş anlam aralığına sahip olan siyah rengin günümüz kadın giyim modasının vazgeçilmez rengi olma nedenlerinin sorgulanması amacı ile hazırlanmıştır. Bu amaç doğrultusunda, siyah rengin tarihsel süreçte ve farklı kültürlerde yeri ve önemi incelenmiş, mitolojiler, efsaneler, destanlar ve geleneklerde yüklenen sembolik anlamları tespit edilmiştir. Dönem ve kültürlere göre siyah rengin din, siyasal, ekonomik, sanat, toplumsal kurallar ve değişimlerden nasıl etkilendiği ve anlam bakımından olumlu ve olumsuz kazanımları örneklerle ele alınmıştır.
Konu; siyah rengin kültürlere göre sembolik anlam ve psikolojik etkileri, toplumsal, sosyal, kültürel faktörler ve giyim kodları yönünden giyime yön veren bireysel ve toplumsal davranış biçimleriyle, giysinin işlevselliği ve simgesel kullanımı açısından incelenmiştir. Bu etkilerin kadın giyim modasında siyah renk kullanımına yansımaları tarihsel süreçte ele alınmış, siyah rengin yoğun kullanıldığı dönemler belirlenmiştir. Belirlenen dönemler ve bu etkiler kapsamında, siyah renge yüklenen sembolik anlamlar tespit edilmiş ve moda eğilimleriyle bağlantıları kurulmuştur. Siyah rengi tasarımlarında kullanan modacılar belirlenerek, tasarım felsefeleri ve bu rengi kullanım nedenlerini ortaya koyan koleksiyon analizleri yapılmıştır.
SH-wave generation by dislocation sources—A numerical study
Authors: Herrmann Robert B. 
Published: September 2021

abstract
A numerical technique is presented for attaining the SH-wave contribution to tangential displacements due to point dislocation sources in a plane layered Earth. The method uses contour integration in the complex k-plane and includes the contribution of branch line integrals along the real and imaginary axes of the k-plane as well as poles along the real axis. Examples are provided to illustrate the effect of neglecting the P-SV contribution to tangential displacements, the effect of improper truncation in estimating far-field time histories, as well as the relative contribution of the various singularities in the complex k-plane to the solution.
Earthquake recurrence intervals and plate tectonics
Authors: Molnar Peter 
Published: September 2021

abstractThe frequency of occurrence of earthquakes with different seismic moments is expressed in terms of the rate of slip on a fault and to the largest seismic moment likely to occur in the region. Beginning from the Gutenberg-Richter empirical expression relating the relative recurrence of events with different magnitudes and using another empirical relation between magnitude and seismic moment, the relative number of events with seismic moment greater than or equal to Mo is given by N(Mo) = αMo−β. β can be determined from parameters in these empirical expressions. From average rates of slip on faults, this expression can be used to give the recurrence rates for events of different seismic moment: α = (1−β)MoΣ/Momax1−β where Momax is the maximum possible seismic moment in a region, and MoΣ is the average rate of occurrence of the seismic moment. On a fault of area A, with shear modulus μ, and long-term average rate of slip v, MoΣ = μAv. A similar expression can be given for α for regions where deformation is distributed over a broad area without a major throughgoing fault. Using rates of convergence at island arcs determined from plate motions for the last 5 m.y., the calculated frequency of occurrence of earthquakes with large seismic moments agrees well with the historic record. At present, uncertainties in the requisite parameters and in assumptions on which the recurrence relation is based, however, make such an approach only marginally better than reliance on the historic record alone. With more data constraining β, the largest possible seismic moments, the role of fault creep, and long-term rates of slip or deformation, however, this approach to seismic risk should be a more reliable predictor of recurrence rates than the existing historic record. As an example, the formulas are applied to the southeastern Caribbean.
The July 27, 1976 Tangshan, China earthquake—A complex sequence of intraplate events
Authors: Butler Rhett , Stewart Gordon S. , Kanamori Hiroo 
Published: September 2021

abstract
The Tangshan earthquake (Ms = 7.7), of July 27, 1976 and its principal aftershock (Ms = 7.2), which occurred 15 hr following the main event, resulted in the loss of life of over 650,000 persons in northeast China. This is the second greatest earthquake disaster in recorded history, following the 1556 Shensi Province, Chinese earthquake in which at least 830,000 persons lost their lives. Detailed analyses of the teleseismic surface waves and body waves are made for the Tangshan event. The major conclusions are: (1) The Tangshan earthquake sequence is a complex one, including strike-slip, thrust, and normal-fault events. (2) The main shock, as determined from surface waves, occurred on a near vertical right-lateral strike-slip fault, striking N40°E. (3) A seismic moment of 1.8 × 1027 dyne-cm is obtained. From the extent of the aftershock zone and relative location of the main shock epicenter, symmetric (1:1) bilateral faulting with a total length of 140 km may be inferred. If a fault width of 15 km is assumed, the average offset is estimated to be 2.7 meters with an average stress drop of about 30 bars. (4) The main shock was initiated by an event with a relatively slow onset and a seismic moment of 4 × 1026 dyne-cm. The preferred fault-plane solution, determined from surface-wave analyses, indicates a strike 220°, dip 80°, and rake −175°. (5) Two thrust events follow the strike-slip event by 11 and 19 sec, respectively. They are located south to southwest of the initial event and have a total moment of 8 × 1025 dyne-cm. This sequence is followed by several more events. (6) The principal aftershock was a normal-fault double event with the fault planes unconstrained by the P-wave first motions. Surface waves provide additional constraints to the mechanism to yield an oblique slip solution with strike N120°E, dip 45°SW, and rake −30°. A total moment of 8 × 1026 dyne-cm is obtained. (7) The triggering of lesser thrust and normal faults by a large strike-slip event in the Tangshan sequence has important consequences in the assessment of earthquake hazard in other complex strike-slip systems like the San Andreas.
Vertical soil-structure interaction effects
Authors: Little R. R. , Raftopoulos D. D. 
Published: September 2021

abstract
An analytical expression describing the three-dimensional vertical soil-structure interaction effects is developed using Laplace and Hankel transformation techniques. Utilizing these transformation techniques and normal mode theory of vibration, an N-mass structural model is coupled to an elastic half-space representing the earth. The resulting interaction equation is solved by numerical iteration techniques for a model of a nuclear power plant subjected to actual earthquake ground excitation. The effects of the soil-structure interaction are evaluated by comparing free-field acceleration spectrum response curves with similar curves determined from the foundation motion. These effects are found to be significant for structures typical of modern nuclear power plants subjected to seismic ground motions.
The Lompoc, California, earthquake (November 4, 1927;M= 7.3) and its aftershocks
Authors: Hanks Thomas C. 
Published: September 2021

abstractSeismological observations local to the 1927 earthquake suggest an epicenter for it near 34.6°N, 120.9°W. These observations include S-P times for the immediate aftershocks recorded at four stations in southern California; S-P times reported for the main shock at Berkeley and Lick Observatory by P. Byerly; and a time-decaying (1934 to 1969) zone of seismicity centered offshore of Point Arguello, herein identified as the aftershock zone of the 1927 earthquake. This location is approximately 40 km southwest of the teleseismic location for the 1927 earthquake recently offered by W. Gawthrop, although a location intermediate to the one proposed here and the one by Gawthrop would satisfy uncertainties associated with both locations. Even so, the location farther offshore is suggested by the near absence of strong shaking in the adjacent coastal region, which seemingly precludes a near-coastal location for an earthquake of this magnitude. Furthermore, unpublished teleseismic first-motion data of G. Stewart and analysis of the distortion of a geodetic quadrilateral by J. Savage and W. Prescott argue against a faulting mechanism for the 1927 earthquake that involves predominantly right-lateral slip on a near-coastal and northwesterly striking fault of the San Andreas type.
Further study of spectral composition ofPcodas of earthquakes and explosions
Authors: Evernden J. F. , Kohler W. M. 
Published: September 2021

abstractThe spectral compositions (bandwidth 0.4 to 4.5 Hz) of the P codas of 108 explosions and 225 earthquakes recorded at LASA are the basis of a technique by which all earthquakes studied are discriminated successfully from all Semipalatinsk explosions. Such complete separation is not achieved, however, for the full set of presumed Russian explosions. The lack of detectable change in frequency content of P signals in the distance range 30° to 90° suggests a very high Qp value for the central mantle. This result, together with the observed rate of amplitude decay for long-period S waves, implies Qs for the central mantle is high while Qs values for the crust-upper mantle and lower mantle are very low.
Wave propagation from extended, asymmetric surface sources in an elastic half-space
Authors: Maiti N. C. , Mitra M. 
Published: September 2021

abstract
A procedure is given for the exact determination of the displacement produced in a half-space by arbitrary stresses acting on the surface. Solutions have been obtained for three different impulsive stress distributions acting on a circular portion of the surface and some common features of the solutions are examined. Numerical values of the surface displacement are exhibited graphically in the three cases showing that the pulses comprising the surface motion are oscillatory.
Earthquakes in Lassen Volcanic National Park, California
Authors: Klein Fred W. 
Published: September 2021

abstract
A small seismograph network of six stations now monitors earthquakes in and near Lassen Volcanic National Park. The first 14 months of recording has revealed a northwest-trending seismic zone passing through the park. This zone is the resolved equivalent of a diffuse zone of historical epicenters passing through Lassen Park and Truckee, California, and is parallel to nearby lineaments in California, Oregon, and Nevada recognized from surface geology. Three dense concentrations of earthquakes correlate very closely with three geothermal areas. One concentration also outlines the north and east sides of the 4-km-diameter Mt. Tehama caldera. The recent dacite plug domes of Lassen Peak and Chaos Crags are nearly aseismic, however. Several approximate focal mechanism solutions indicate primarily normal faulting with east-west extension. This implies the northwest-trending seismic zone is undergoing extension and right-lateral shear. Extension directions near the center of the network display a radial symmetry that could be caused by a broad updoming or magma injection centered near Lassen Peak or Chaos Crags.
On the relation between modified Mercalli intensity and body-wave magnitude
Authors: Nuttli Otto W. , Bollinger G. A. , Griffiths Donald W. 
Published: September 2021

abstractThis paper is concerned with estimating body-wave magnitude, mb, from the intensity distribution of an earthquake. Initially, it is assumed that modified Mercalli (MM) intensity values are directly related to the (A/T)z values of 1-Hz, Lg-wave ground motion. By comparison with the intensity values of a reference earthquake, magnitudes are calculated for 41 western and central United States earthquakes. Magnitudes of these earthquakes also are determined independently, in the conventional manner, using teleseismic P-wave amplitudes. Comparison of the two sets of magnitude values indicates that the assumed relation between 1-Hz, Lg-wave (A/T)z values and MM intensity does not hold exactly over the mb range of 4.0 to 6.2. An empirical equation is derived to adjust the mb values obtained from intensity data so that they agree with the teleseismic P-wave magnitudes.The method then is applied to estimate mb of some historical earthquakes which occurred prior to 1962. These include the set for which Kanamori and Jennings (1978) estimated ML from strong-motion accelerograms. Some noteworthy United States earthquakes also are considered. These include: the 1811 New Madrid earthquake for which mb is estimated to be 7.3; the 1886 Charleston, South Carolina earthquake, for which mb is estimated to be 6.6 to 6.9; the 1897 Giles County, Virginia earthquake, for which mb is estimated to be 5.8; the 1906 San Francisco, California earthquake, for which mb is estimated to be 6.8 to 7.1.The intensity-attenuation method cannot be used for estimating mb of all historical earthquakes because the intensity data are not always adequate. In some cases, however, the total felt area or the area enclosed by the Modified Mercalli IV isoseism can be determined. It was found that empirical equations relating mb to these areas, which were derived for central and northeastern United States earthquakes, also apply for events in the southeast. These empirical methods are used to estimate mb values for a set of historical Virginia earthquakes.
Time functions appropriate for nuclear explosions
Authors: Burdick L. J. , Helmberger D. V. 
Published: September 2021

abstractThe source-time function of megaton class nuclear explosions has been determined by modeling teleseismic short- and long-period body waves with synthetic seismograms. A simple analytic expression for the time function was used to closely match observations from both Novaya Zemlya and the U.S. test site at Amchitka. It was found that the time functions of all the events have a substantial overshoot. It was also found that, although the durations of the time functions did appear to depend on yield, the effect was very difficult to observe even in short-period records. All synthetics were computed by assuming a simple point source in a layered elastic half-space. It was not necessary to appeal to any nonlinear processes in the source region to explain the observations. Numerical calculations are presented to show that tectonic release triggered by earthquakes does not have a substantial effect on the P waves unless the long-period level of the tectonic event is as large or larger than the long-period level of the explosion. The pS wave, on the other hand, is shown to be very sensitive to even a moderate amount of tectonic release.
Shear-wave velocity at the base of the mantle from profiles of diffracted SH waves
Authors: Okal Emile A. , Geller Robert J. 
Published: September 2021

abstract
Profiles of SH waves diffracted around the core (Sd) for three deep events at stations across North America and the Atlantic (Δ = 92° to 152°) are used to determine the properties of the lower mantle in the vicinity of the core-mantle boundary (CMB). The S-wave velocity above the CMB is found to be βc = 7.22 ± 0.1 km/sec, in agreement with gross earth models, but higher than previously reported values from direct measurements of Sd. The frequency imdependence of the Sd ray parameter argues strongly against the possibility of a low-velocity zone immediately above the core mantle boundary.
We compute synthetic seismograms for Sd by summing normal modes. A comparison of the present data with a synthetic profile for earth model 1066A gives excellent agreement at periods greater than 45 seconds. Synthetics for other models are used to substantially constrain the possibility of significant rigidity of the uppermost layer of the core.