bluuebunny/crossref_metadata_2025 huggingface dataset:
Chapter 20 The Abu Mahara Group (Ghubrah and Fiq formations), Jabal Akhdar, Oman
Authors: Allen Philip A. , Leather Jonathan , Brasier Martin D. , Rieu Ruben , McCarron Margaret , Guerroué Erwan le , Etienne James L. , Cozzi Andrea
Published: December 2011

The Abu Mahara Group (
c.
725–<645 Ma) of the Huqf Supergroup in the Jabal Akhdar of northern Oman hosts two glacial successions in the Ghubrah and Fiq formations, separated by the <50-m-thick volcanogenic Saqlah Member. The >400-m-thick Ghubrah Formation is dominated by distal glaciogenic rainout diamictites, laminites and turbiditic siltstones, whereas the <1.5-km-thick Fiq Formation exhibits a cyclical stratigraphy of proximal and distal marine glaciogenic facies, and non-glacial sediment gravity flow and shallow marine facies. The Fiq Formation is overlain by a transgressive, isotopically light carbonate known as the Hadash Formation. A tuffaceous ash interbedded with glacial diamictites of the Ghubrah Formation in Wadi Mistal has yielded a U–Pb zircon age of 713.7±0.5 Ma. The Fiq Formation contains detrital zircons as young as 645 Ma. The use of the CIA (Chemical Index of Alteration) shows the Fiq Formation to be climatically cyclic, with alternations of high and low chemical weathering of contemporary land surfaces driven by phases of glaciation and deglaciation. The transgression into the post-glacial Masirah Bay Formation is marked by a major increase in chemical weathering.
Chapter 21 The Tambien Group, Northern Ethiopia (Tigre)
Authors: Miller Nathan R. , Avigad Dov , Stern Robert J. , Beyth Michael
Published: December 2011

The Tambien Group of northern Ethiopia (Tigre), with probable correlatives in Eritrea, is a 2–3-km-thick siliciclastic–carbonate succession that was deposited in an intra-oceanic arc platform setting within the southern Arabian–Nubian Shield (ANS) area (southern extension of the Nakfa Terrane) of the Mozambique Ocean. Its deposition occurred prior to ocean closure between converging fragments of East and West Gondwana and concomitant structural emergence of the East African Orogen (EAO). The Tambien Group is well exposed and best studied in the Mai Kenetal and Negash synclinoria, where litho- and chemostratigraphy (including δ
13
C
carb
,
87
Sr/
86
Sr) provide the basis for a composite reference section. Two glaciogenic intervals have been suggested from exposures within the Didikama and Matheos Formation in the Negash Synclinorium. No reliable palaeomagnetic data exist to constrain the palaeolatitude of Tambien Group deposition and the southern ANS, but palaeogeographic reconstructions and evaporite pseudomorphs in lower carbonate units (Didikama Formation) imply low to intermediate latitudes (<45°). Integration of available geochronological information (regional magmatism and detrital zircon) suggests
c.
775–660 Ma as a plausible window constraining deposition of the prospective glacial intervals.

The Tambien Group appears to preserve a coherent chemostratigraphic framework that can be effectively subdivided according to shifts in δ
13
C
carb
polarity [polarity intervals A (+), B (–), C (+), D (–)]. Slates underlying and interstratified with polarity interval A carbonate preserve evidence of extreme chemical weathering that lessened prior to deposition of polarity interval B carbonate. Tambien Group carbonate units have sedimentological characteristics consistent with both shallow and deeper marine depositional settings. The lower prospective glacial interval lacks diagnostic sedimentological evidence of synglacial deposition, but is overlain by negative δ
13
C carbonate (polarity interval B) with sedimentological characteristics consistent with well-documented cap-carbonate successions. The upper prospective glacial interval in the Negash Synclinorium (Matheos Diamictite) best exhibits characteristics consistent with glaciogenic deposition (matrix-supported polymictic clasts, possible dropstones, possible bullet-nosed and striated clasts). In contrast to pericratonic rift margin settings that are common for Cryogenian glaciogenic deposits, palaeogeographic reconstructions for the 775–660 Ma timeframe place northern Ethiopia within an intra-oceanic setting that was likely far removed from cratonic hinterlands. More work on Tambien Group sedimentology, geochronology and palaeogeography is required to better evaluate the extent and timing of glacial conditions associated with the prospective glaciogenic intervals.

Supplementary material:

Supplementary Table 21.1 of Tambien Group geochronological age constraints is available at
http://www.geolsoc.org.uk/SUP18462
.
Chapter 29 The Tsagaan Oloom Formation, southwestern Mongolia
Authors: Macdonald Francis A.
Published: December 2011

The Tsagaan Oloom Formation (Fm.) in southwestern Mongolia contains two Neoproterozoic glacial deposits, with diamictite in the Maikhan Ul Member (Mb.) and in the Khongoryn Mb., which are separated by over 500 m of limestone. The Maikhan Ul Mb. ranges in thickness between 5 m and greater than 300 m, expanding in deeper-water sections towards the SW, where it is composed of two massive diamictites separated by over 100 m of sandstone, siltstone and shale. The basal 10 m of the overlying Tayshir Mb. of the Tsagaan Oloom Fm. consists of a fine-laminated, dark grey limestone. The Khongoryn Mb. is composed primarily of limestone clasts in a shale matrix, and is between 0 and 23 m thick. The overlying Ol Mb. contains sedimentary structures characteristic of basal Ediacaran cap carbonates including micropeloids, tubestone stromatolites, giant wave ripples and former aragonite crystal fans. U–Pb evaporation ages from zircons in the underlying Dzabkhan Volcanics constrain the Tsagaan Oloom Fm. to <773 Ma, and tuffs within the Maikhan Ul and Tayshir members testify to the potential for additional geochronology. The Cryogenian organic-rich limestone of the Tayshir Mb., which lies between the two glacial deposits, is ideally suited for geochemical studies and has been the subject of several carbon, strontium and rare earth element investigations. Limited palaeomagnetic studies suggest a mid- to low-latitude position of the Dzabkhan platform during deposition of the glaciogenic strata, and additional studies are in progress.
Chapter 31 The Blaini Formation of the Lesser Himalaya, NW India
Authors: Etienne James L. , Allen Philip A. , Guerroué Erwan le , Heaman Larry , Ghosh Sumit K. , Islam Rafique
Published: December 2011

Neoproterozoic glaciogenic deposits crop out widely across the Lesser Himalaya fold and thrust belt in NW India. Underlain by the siliciclastic Simla and Jaunsar Groups, the Blaini Formation (Fm.) includes at least two thick and regionally extensive diamictite units, separated by siliciclastics and argillites and capped by a pink microcrystalline dolomite. A glaciogenic origin is supported by the presence of relatively abundant striated clasts and the local preservation of polished and striated pavement on underlying Simla Group clastics. The cap dolostone is isotopically light with respect to both
13
C and
18
O, which show strong covariance. The Blaini is ubiquitously deformed, incorporated in regional-scale folds and thrusts, and exhibits locally intensive intra-formational deformation. Until recently, geochronological constraints have remained poor, but new detrital zircon ages from diamictite samples provide a maximum age limit of 692±18 Ma (
207
Pb/
206
Pb). Reliable palaeomagnetic data are required to constrain the position of this important passive continental margin in palaeogeographical reconstructions.
Chapter 33 Neoproterozoic glaciogenic diamictites of the Tarim Block, NW China
Authors: Zhu Maoyan , Wang Haifeng
Published: December 2011

Neoproterozoic glaciogenic outcrops are mostly limited to the southwestern and northwestern margins of the Tarim basin and the Tianshan Mountains. Only two glaciogenic diamictites are recorded in the Neoproterozoic successions from the Tielikeli and Aksu-Wusi areas of the Tarim basin. The lower diamictite from the Polong Formation in the Tielikeli area is
c.
800 m thick. The upper diamictite in the area is very thin (Yutang diamictite, 10 m; Yulmeinak diamictite, 51 m). In contrast to the Tarim basin, the Neoproterozoic successions along the northern margin of the Tarim Block in the Tianshan Mountains record three or four glaciogenic diamictites, which are well developed and crop out in the Qurugtagh area. Although the glaciogenic nature of the oldest Beiyixi diamictite remains questionable, all other diamictites (Altungol, Tereeken and Hankalchough) exhibit distinct glaciogenic sedimentary features. SHRIMP zircon U–Pb dating demonstrate that the Bayisi diamictite was deposited between 740±7 Ma and 725±10 Ma, the Altungol and Tereeken diamictites between 725±10 Ma and 615±6 Ma, respectively, and the Hankalchough diamictite between 615±6 Ma and
c.
542 Ma. Carbonates atop the Altungol, Tereeken and Hankalchough diamictites show distinct C-isotopic values that are typical for those recorded in ‘cap carbonates’ on other continents. The striking similarity between the cap carbonate of the Tereeken and Marinoan-age Nantuo diamictites further support a 635 Ma ‘Marinoan’ age for the Tereeken glaciation. Unlike the 582 Ma Gaskiers glaciations of Newfoundland, the Hankalchough diamictite is possibly <551 Ma, as suggested by C-isotope chemostratigraphy and biostratigraphy, indicating that post-Marinoan glaciations on different continents may be diachronous.

Supplementary material:

Data are available at:
http://www.geolsoc.org.uk/SUP18469
.
Chapter 4 Chemostratigraphy and the Neoproterozoic glaciations
Authors: Halverson Galen P. , Shields-Zhou Graham
Published: December 2011

Although the pre-glacial Proterozoic isotopic record is poorly constrained, it is apparent that the chemical and isotopic composition of the oceans began to change during the early to mid-Neoproterozoic and experienced considerable fluctuations alongside climatic instability during much of the subsequent Cryogenian and Ediacaran periods. The earliest known large negative δ
13
C excursion appears to post-date 811 Ma and fluctuations became progressively more extreme, culminating in the late-Ediacaran ‘Shuram–Wonoka’ anomaly. The negative excursions are commonly associated with pre-glacial and post-glacial times, while extremely high δ
13
C values are characteristic of strata between glaciations. The precise causal mechanism for these excursions is subject to debate. Seawater
87
Sr/
86
Sr rose during the Neoproterozoic, with abrupt increases following deglaciation consistent with enhanced weathering rates. Reported marine sulphate and pyrite δ
34
S data exhibit marked variation through this interval, although the changes are not always consistent within or between sedimentary successions of equivalent age. Iron-speciation studies indicate that much of this variation was caused by fluctuating and low sulphate concentrations in seawater, which at times led to the build-up of ferruginous conditions in the ocean. The application of chemostratigraphy to understanding and correlating the Neoproterozoic glaciations evokes considerable controversy, and many questions persist regarding the reliability and calibration of the δ
13
C,
87
Sr/
86
Sr and δ
34
S record. Nevertheless, the individual glaciations appear to be characterized by distinct combined chemostratigraphic signatures, in large part due to the generally increasing strontium isotope composition of seawater through the Neoproterozoic Era.
Chapter 40 The Kingston Peak Formation in the eastern Death Valley region
Authors: Mrofka David , Kennedy Martin
Published: December 2011

The late Neoproterozoic Kingston Peak Formation (Fm.) is a several-kilometre-thick sedimentary succession primarily influenced by syndepositional tectonism and located in the region around Death Valley, California (Fig. 40.1). Its distribution is divisible into an eastern facies assemblage, the subject of this paper, and a western facies assemblage covered in a separate chapter. The diamictite-bearing Kingston Peak Fm. is bounded by the underlying shallow platform carbonates of the Beck Spring Fm. and overlain by the Noonday Dolomite. There is an absence of direct palaeolatitude or radiometric age constraints and any correlation is based on broad similarities with other coarse-grained strata (diamictite) located in a northward trending belt along the Cordilleran miogeocline. The overlying Noonday Dolomite has been interpreted to be a late Cryogenian ‘cap carbonate’ and shares a set of unique facies associations and isotopic and lithological characteristics with other late Neoproterozoic post-glacial carbonate intervals in Namibia, Canada, Australia and Brazil. Research to date has focused on understanding local basin evolution, glacial sedimentology, correlation between the eastern and western facies assemblages and initiation and development of the North American Cordillera. The intimate association of tectonic and glacial facies with rapid local thickness and facies changes corresponding with syn-sedimentary faulting is the most distinctive stratigraphic characteristic of the Kingston Peak Fm. The complex local stratigraphy complicates correlation both within the Death Valley region as well as globally, and pending absolute age dates, does not fit easily with conventional Cryogenian Period glacial models identifying two or more discrete ice ages.
Chapter 47 The Bebedouro Formation, Una Group, Bahia (Brazil)
Authors: Guimarães J. T. , Misi A. , Pedreira A. J. , Dominguez J. M. L.
Published: December 2011

The Bebedouro Formation (Fm.) is a Neoproterozoic glaciogenic succession at the base of the Una Group on the São Francisco Craton. The glaciogenic sequence is composed of diamictites, pelites and sandstones with a variety of lithofacies that are grouped into four associations: (i) ice-contact, (ii) pro-glacial, (iii) ice-rafted and (iv) aeolian (extraglacial). Thus, the Bebedouro Fm. is interpreted to have been deposited in a shelf marine environment where glacio-proximal sedimentation dominated. It variably overlies Palaeoproterozoic/Archaean basement and Mesoproterozoic metasedimentary rocks of the Chapada Diamantina Group.

The overlying carbonate succession (Salitre Fm.) is informally subdivided into five mappable units. Unit C, at the base, is composed of red argillaceous dolostone with typical negative δ
13
C signatures averaging –5.1‰ (VPDB). Unit B consists of grey laminated limestones that grade upward into grey dolostone with tepee structures of Unit B1; both have δ
13
C values around 0‰. The overlying Unit A consists of interbeds of greyish marl, shales and siltstones grading upward into massive black organic-rich limestone with oolitic and pisolitic beds of Unit A1. Positive δ
13
C signatures averaging +8.5‰ VPDB characterize the black limestones of Unit A1.
87
Sr/
86
Sr ratios of well-preserved samples of these carbonate units show values of 0.70745 and 0.70765. These units can be correlated litho- and chemostratigraphically with formations of the Bambuí Group (São Francisco Basin) to the west.
Chapter 48 Neoproterozoic successions of the São Francisco Craton, Brazil: the Bambuí, Una, Vazante and Vaza Barris/Miaba groups and their glaciogenic deposits
Authors: Misi Aroldo , Kaufman Alan J. , Azmy Karem , Dardenne Marcel Auguste , Sial Alcides Nóbrega , de Oliveira Tolentino Flávio
Published: December 2011

The Neoproterozoic successions of the São Francisco Craton are primarily represented by the Bambuí and Una groups, deposited in cratonic epicontinental basins, and by the Vazante and Vaza Barris/Miaba groups, which accumulated on passive margins on the edges of the craton. The epicontinental basins comprise three megasequences: glaciogenic, carbonate platform (marine) and dominantly continental siliciclastics. Possible correlative sequences are observed in the passive margin deposits. At least two major transgressive–regressive sea-level cycles occurred during the evolution of the carbonate megasequence, which lies above glaciomarine diamictites of probable early Cryogenian (i.e. Sturtian) age. C, O, Sr and S isotope trends from analyses of well-preserved samples, together with lithostratigraphic observations, provide reasonable correlations for most of the Neoproterozoic successions of the São Francisco Craton. The
87
Sr/
86
Sr record of these successions, ranging from 0.70769 to 0.70780, supports the proposed correlation with the Bambuí, Una and Vaza/Barris successions, and with the basal units of the Vazante Group. In addition, C-isotope positive excursions ranging from +8.7 to +14‰ and negative excursions from –5.7 to –7‰ VPDB in the Bambuí, Una and Vaza-Barris successions provide key markers for correlations. The precise ages of the sedimentation in these successions remains a matter of debate, but organic shales of two units of the Vazante Group have been dated by Re–Os techniques in two different laboratories, both yielding Mesoproterozoic ages. The Neoproterozoic and Mesoproterozoic successions preserve significant glaciogenic deposits.
Chapter 54 The controversial stratigraphy of the glacial deposits in the Tandilia System, Argentina
Authors: Pazos P. J. , Rapalini A.
Published: December 2011

In the Ediacaran–Cambrian Tandilia System of central Argentina, the glacial origin of the thin (10 m) Sierra del Volcán Formation (Fm.) has been recognized for many years (
Spalletti & del Valle 1984
), being the first undisputed glacial deposits recorded in the Río de la Plata craton. It consists of three units: (i) a basal polymictic diamictite with a kaolin-rich matrix, (ii) a middle pelite with heterolithic levels, undulatory stratification, symmetric ripples, and outsized clasts previously interpreted as dropstones, and (iii) an upper polymictic diamictite with subtle normal grading. Here, this poorly age-constrained formation is reviewed from a stratigraphic and regional context and compared with other putative glaciogenic intervals at the base of the Cerro Largo Fm. and in the Punta Mogotes borehole.
Chapter 66 Mid-Ediacaran ice-rafting in the Adelaide Geosyncline and Officer Basin, South Australia
Authors: Gostin Victor A. , McKirdy David M. , Webster Lynn J. , Williams George E.
Published: December 2011

Sedimentary features characteristic of ice-rafting are present in the Bunyeroo Formation (Wilpena Group) of the Adelaide Geosyncline and in the coeval Dey Dey Mudstone (Ungoolya Group) of the eastern Officer Basin (Figs 66.1 & 66.2), providing evidence of a mid-Ediacaran glacial climate in South Australia. The Acraman asteroid impact, a negative shift in marine δ
13
C, and a major acritarch turnover coincided with this frigid epoch.
Involvement of the extracellular signal-regulated kinase 1/2 signaling pathway in amylin's eating inhibitory effect
Authors: Potes Catarina Soares , Boyle Christina Neuner , Wookey Peter John , Riediger Thomas , Lutz Thomas Alexander
Published: December 2011

Peripheral amylin inhibits eating via the area postrema (AP). Because amylin activates the extracellular-signal regulated kinase 1/2 (ERK) pathway in some tissues, and because ERK1/2 phosphorylation (pERK) leads to acute neuronal responses, we postulated that it may be involved in amylin's eating inhibitory effect. Amylin-induced ERK phosphorylation (pERK) was investigated by immunohistochemistry in brain sections containing the AP. pERK-positive AP neurons were double-stained for the calcitonin 1a/b receptor, which is part of the functional amylin-receptor. AP sections were also phenotyped using dopamine-β-hydroxylase (DBH) as a marker of noradrenergic neurons. The effect of fourth ventricular administration of the ERK cascade blocker U0126 on amylin's eating inhibitory action was tested in feeding trials. The number of pERK-positive neurons in the AP was highest ∼10–15 min after amylin treatment; the effect appeared to be dose-dependent (5–20 μg/kg amylin). A portion of pERK-positive neurons in the AP carried the amylin-receptor and 22% of the pERK-positive neurons were noradrenergic. Pretreatment of rats with U0126 decreased the number of pERK-positive neurons in the AP after amylin injection. U0126 also attenuated the ability of amylin to reduce eating, at least when the animals had been fasted 24 h prior to the feeding trial. Overall, our results suggest that amylin directly stimulates pERK in AP neurons in a time- and dose-dependent manner. Part of the AP neurons displaying pERK were noradrenergic. At least under fasting conditions, pERK was shown to be a necessary part in the signaling cascade mediating amylin's anorectic effect.
Melatonin supplementation alters uteroplacental hemodynamics and fetal development in an ovine model of intrauterine growth restriction
Authors: Lemley Caleb O. , Meyer Allison M. , Camacho Leticia E. , Neville Tammi L. , Newman David J. , Caton Joel S. , Vonnahme Kimberly A.
Published: December 2011

Using a mid- to late-gestation ovine model of intrauterine growth restriction (IUGR), we examined uteroplacental blood flow and fetal growth during melatonin supplementation as a 2 × 2 factorial design. At day 50 of gestation, 32 ewes were supplemented with 5 mg of melatonin (MEL) or no melatonin (CON) and were allocated to receive 100% [adequate; (ADQ)] or 60% [restricted (RES)] of nutrient requirements until day 130 of gestation. Umbilical artery blood flow was increased from day 60 to day 110 of gestation in MEL vs. CON dams, while umbilical artery blood flow was decreased from day 80 to day 110 of gestation in RES vs. ADQ dams. At day 130 of gestation, uteroplacental hemodynamics, measured under general anesthesia, and fetal growth were evaluated. Uterine artery blood flow was decreased in RES vs. ADQ dams, while melatonin supplementation did not affect uterine artery blood flow. Total placentome weight and placentome number were not different between treatment groups. Fetal weight was decreased by nutrient restriction. Abdominal girth and ponderal index were increased in fetuses from MEL-ADQ dams vs. all other groups. Fetal biparietal distance was decreased in CON-RES vs. CON-ADQ dams, while melatonin supplementation rescued fetal biparietal distance. Fetal kidney length and width were increased by maternal melatonin treatment. Fetal cardiomyocyte area was altered by both maternal melatonin treatment and nutritional plane. In summary, melatonin may negate the consequences of IUGR during specific abnormalities in umbilical blood flow as long as sufficient uterine blood perfusion is maintained during pregnancy.
The pendrin anion exchanger gene is transcriptionally regulated by uroguanylin: a novel enterorenal link
Authors: Rozenfeld Julia , Tal Osnat , Kladnitsky Orly , Adler Lior , Efrati Edna , Carrithers Stephen L. , Alper Seth L. , Zelikovic Israel
Published: December 2011

The pendrin/SLC26A4 Cl−/HCO3− exchanger, encoded by the PDS gene, is expressed in cortical collecting duct (CCD) non-A intercalated cells. Pendrin is essential for CCD bicarbonate secretion and is also involved in NaCl balance and blood pressure regulation. The intestinal peptide uroguanylin (UGN) is produced in response to oral salt load and can function as an “intestinal natriuretic hormone.” We aimed to investigate whether UGN modulates pendrin activity and to explore the molecular mechanisms responsible for this modulation. Injection of UGN into mice resulted in decreased pendrin mRNA and protein expression in the kidney. UGN decreased endogenous pendrin mRNA levels in HEK293 cells. A 4.2-kb human PDS (h PDS) promoter sequence and consecutive 5′ deletion products were cloned into luciferase reporter vectors and transiently transfected into HEK293 cells. Exposure of transfected cells to UGN decreased h PDS promoter activity. This UGN-induced effect on the h PDS promoter occurred within a 52-bp region encompassing a single heat shock element (HSE). The effect of UGN on the promoter was abolished when the HSE located between nt −1119 and −1115 was absent or was mutated. Furthermore, treatment of HEK293 cells with heat shock factor 1 (HSF1) small interfering RNA (siRNA) reversed the UGN-induced decrease in endogenous PDS mRNA level. In conclusion, pendrin-mediated Cl−/HCO3− exchange in the renal tubule may be regulated transcriptionally by the peptide hormone UGN. UGN exerts its inhibitory activity on the h PDS promoter likely via HSF1 action at a defined HSE site. These data define a novel signaling pathway involved in the enterorenal axis controlling electrolyte and water homeostasis.
Physical model of coherent potentials measured with different electrode recording site sizes
Authors: Nelson Matthew J. , Pouget Pierre
Published: December 2011

A question that still complicates interpretation of local field potentials (LFPs) is how electrode properties like impedance, size, and shape affect recorded LFPs. In addition, how any such effects should be considered when comparing LFP, electroencephalogram (EEG), or electrocorticogram (ECoG) data has not been clearly described. A generally accepted concrete physical model describes that an electrode records the spatial average of the voltage across its uninsulated tip, yet the effects of this spatial averaging on recorded coherence have never been modeled. Using simulations based on this physical model, we show here that for any effects to occur, a spatial voltage gradient on a scale smaller than an electrode's recording site must exist over the site's surface. When this occurs, larger electrodes on average report higher coherence between locations, with the effect continuously increasing as the voltage profile over the extent of the recording site is increasingly nonuniform. We quantitatively compared published coherence estimates of LFP, ECoG, and EEG data across a range of studies and found a possible modest effect of electrode size in published ECoG data only. We used the model to quantify the expected coherence for any electrode size in relation to any given spatial frequency of a voltage profile. From this and existing estimates of the spread of voltages underlying each of these data types, our simulations quantitatively agree with the published data and importantly suggest that LFP coherence will be independent of recording site size within the range of microelectrodes typically used for extracellular recordings.
Extrastriatal D2-like receptors modulate basal ganglia pathways in normal and parkinsonian monkeys
Authors: Hadipour-Niktarash Arash , Rommelfanger Karen S. , Masilamoni Gunasingh J. , Smith Yoland , Wichmann Thomas
Published: December 2011

According to traditional models of the basal ganglia-thalamocortical network of connections, dopamine exerts D2-like receptor (D2LR)-mediated effects through actions on striatal neurons that give rise to the “indirect” pathway, secondarily affecting the activity in the internal and external pallidal segments (GPi and GPe, respectively) and the substantia nigra pars reticulata (SNr). However, accumulating evidence from the rodent literature suggests that D2LR activation also directly influences synaptic transmission in these nuclei. To further examine this issue in primates, we combined in vivo electrophysiological recordings and local intracerebral microinjections of drugs with electron microscopic immunocytochemistry to study D2LR-mediated modulation of neuronal activities in GPe, GPi, and SNr of normal and MPTP-treated (parkinsonian) monkeys. D2LR activation with quinpirole increased firing in most GPe neurons, likely due to a reduction of striatopallidal GABAergic inputs. In contrast, local application of quinpirole reduced firing in GPi and SNr, possibly through D2LR-mediated effects on glutamatergic inputs. Injections of the D2LR antagonist sulpiride resulted in effects opposite to those of quinpirole in GPe and GPi. D2 receptor immunoreactivity was most prevalent in putative striatal-like GABAergic terminals and unmyelinated axons in GPe, GPi, and SNr, but a significant proportion of immunoreactive boutons also displayed ultrastructural features of glutamatergic terminals. Postsynaptic labeling was minimal in all nuclei. The D2LR-mediated effects and pattern of distribution of D2 receptor immunoreactivity were maintained in the parkinsonian state. Thus, in addition to their preferential effects on indirect pathway striatal neurons, extrastriatal D2LR activation in GPi and SNr also influences direct pathway elements in the primate basal ganglia under normal and parkinsonian conditions.
Facilitation of learning induced by both random and gradual visuomotor task variation
Authors: Turnham Edward J. A. , Braun Daniel A. , Wolpert Daniel M.
Published: December 2011

Motor task variation has been shown to be a key ingredient in skill transfer, retention, and structural learning. However, many studies only compare training of randomly varying tasks to either blocked or null training, and it is not clear how experiencing different nonrandom temporal orderings of tasks might affect the learning process. Here we study learning in human subjects who experience the same set of visuomotor rotations, evenly spaced between −60° and +60°, either in a random order or in an order in which the rotation angle changed gradually. We compared subsequent learning of three test blocks of +30°→−30°→+30° rotations. The groups that underwent either random or gradual training showed significant ( P < 0.01) facilitation of learning in the test blocks compared with a control group who had not experienced any visuomotor rotations before. We also found that movement initiation times in the random group during the test blocks were significantly ( P < 0.05) lower than for the gradual or the control group. When we fit a state-space model with fast and slow learning processes to our data, we found that the differences in performance in the test block were consistent with the gradual or random task variation changing the learning and retention rates of only the fast learning process. Such adaptation of learning rates may be a key feature of ongoing meta-learning processes. Our results therefore suggest that both gradual and random task variation can induce meta-learning and that random learning has an advantage in terms of shorter initiation times, suggesting less reliance on cognitive processes.
Sound-identity processing in early areas of the auditory ventral stream in the macaque
Authors: Kuśmierek Paweł , Ortiz Michael , Rauschecker Josef P.
Published: December 2011

Auditory cortical processing is thought to be accomplished along two processing streams. The existence of a posterior/dorsal stream dealing, among others, with the processing of spatial aspects of sound has been corroborated by numerous studies in several species. An anterior/ventral stream for the processing of nonspatial sound qualities, including the identification of sounds such as species-specific vocalizations, has also received much support. Originally discovered in anterolateral belt cortex, most recent work on the anterior/ventral pathway has been performed on far anterior superior temporal (ST) areas and on ventrolateral prefrontal cortex (VLPFC). Regions of the anterior/ventral stream near its origin in early auditory areas have been less explored. In the present study, we examined three early auditory regions with different anteroposterior locations (caudal, middle, and rostral) in awake rhesus macaques. We analyzed how well classification based on sound-evoked activity patterns of neuronal populations replicates the original stimulus categories. Of the three regions, the rostral region (rR), which included core area R and medial belt area RM, yielded the greatest classification success across all stimulus classes or between classes of natural sounds. Starting from ∼80 ms past stimulus onset, clustering based on the population response in rR became clearly more successful than clustering based on responses from any other region. Our study demonstrates that specialization for sound-identity processing can be found very early in the auditory ventral stream. Furthermore, the fact that this processing develops over time can shed light on underlying mechanisms. Finally, we show that population analysis is a more sensitive method for revealing functional specialization than conventional types of analysis.
P2Y1 receptor modulation of Ca2+-activated K+ currents in medium-sized neurons from neonatal rat striatal slices
Authors: Coppi E. , Pedata F. , Gibb A. J.
Published: December 2011

ATP signaling to neurons and glia in the nervous system occurs via activation of both P2Y and P2X receptors. Here, we investigated the effects of P2Y1 receptor stimulation in developing striatal medium-sized neurons using patch-clamp recordings from acute brain slices of 7- and 28-day-old rats. Application of the selective P2Y1 receptor agonist 2-(Methylthio) ADP trisodium salt (2-MeSADP; 250 nM) increased outward K+ currents evoked by a ramp depolarization protocol in voltage-clamp recordings. This effect was observed in 59 out of 82 cells (72%) and was blocked completely by the P2Y1 antagonist, 2′-deoxy- N6-methyl adenosine 3′,5′-diphosphate. The averaged 2-MeSADP-sensitive conductance was fitted by the sum of a linear conductance and a Boltzmann relation, giving one-half activation voltage of −14.2 mV and an equivalent charge of 2.91. The 2MeSADP-mediated effect was sensitive to submillimolar concentrations of tetraethylammonium (TEA; 200 μM), to 200 nM iberiotoxin and to 100 nM apamin, suggesting the involvement of both big and small potassium (BK and SK, respectively) calcium-activated channels. In current-clamp experiments, 2-MeSADP decreased depolarization-evoked action potential (AP) firing in all 26 cells investigated, and this effect was reversed by TEA and by apamin but not by iberiotoxin. We conclude that the stimulation of P2Y1 receptors in developing striatal neurons leads to activation of calcium-activated potassium channels [IK(Ca)] of both BK and SK subtypes, the latter responsible for decreasing the frequency of AP firing in response to current injection. Therefore, P2Y1 signaling leading to activation of IK(Ca) may be important in regulating the activity of medium-sized neurons in the striatum.
Interhemispheric connectivity between distinct motor regions as a window into bimanual coordination
Authors: Hinder Mark R.
Published: December 2011

Performing coordinated bimanual movement is a fundamental feature of the human motor system, with imaging techniques revealing the involvement of an extensive network of motor regions in both hemispheres. Using transcranial magnetic stimulation, Liuzzi et al. ( J Neurosci 31: 9111–9117, 2011) recently extended our understanding of the neural correlates of motor actions by showing that the nature of the interhemispheric connectivity between primary and premotor regions may influence motor performance during a bimanual tapping task.
mGluR6 deletion renders the TRPM1 channel in retina inactive
Authors: Xu Ying , Dhingra Anuradha , Fina Marie E. , Koike Chieko , Furukawa Takahisa , Vardi Noga
Published: December 2011

In darkness, glutamate released from photoreceptors activates the metabotropic glutamate receptor 6 (mGluR6) on retinal ON bipolar cells. This activates the G protein Go, which then closes transient receptor potential melastatin 1 (TRPM1) channels, leading to cells' hyperpolarization. It has been generally assumed that deleting mGluR6 would render the cascade inactive and the ON bipolar cells constitutively depolarized. Here we show that the rod bipolar cells in mGluR6-null mice were hyperpolarized. The slope conductance of the current-voltage curves and the current noise were smaller than in wild type. Furthermore, while in wild-type rod bipolar cells, TRPM1 could be activated by local application of capsaicin; in null cells, it did not. These results suggest that the TRPM1 channel in mGluR6-null rod bipolar cells is inactive. To explore the reason for this lack of activity, we tested if mGluR6 deletion affected expression of cascade components. Immunostaining for G protein subunit candidates Gαo, Gβ3, and Gγ13 showed no significant changes in their expression or distribution. Immunostaining for TRPM1 in the dendritic tips was greatly reduced, but the channel was still present in the soma and primary dendrites of mGluR6-null bipolar cells, where a certain fraction of TRPM1 appears to localize to the plasma membrane. Consequently, the lack of TRPM1 activity in the null retina is unlikely to be due to failure of the channels to localize to the plasma membrane. We speculate that, to be constitutively active, TRPM1 channels in ON bipolar cells have to be in a complex, or perhaps require an unidentified factor.
Monoclonal Gammopathy of Undetermined Significance (MGUS) in a Man with Fragile X-associated Tremor/Ataxia Syndrome
Authors: Sumekar Tanjung A. , Ashrani Aneel A. , Winarni Tri I. , Hagerman Randi J.
Published: December 2011

We report the clinical presentation and laboratory findings of a 69-year-old man with fragile X-associated tremor ataxia syndrome (FXTAS), a progressive neurodegenerative disorder, who was noted to have monoclonal gammopathy of undetermined significance (MGUS), a plasma cell proliferative disorder and a precursor disease of multiple myeloma. Both MGUS and FXTAS are associated with microRNA (miRNA) dysregulation. We speculate that individuals with FXTAS may be predisposed to MGUS and further studies are warranted regarding this association.
Cutaneous Manifestations of Thyroid Disease: A Case of Thyroid-Induced Myxedema
Authors: Shroff Anjali , Simpson Gregory
Published: December 2011

The cutaneous manifestations of thyroid disease can be present in the hair, nails, and local or diffuse locations throughout the skin. Traditionally, thyroid-associated mucin deposition is present in a pretibial location on bilateral lower legs. We present a case of a growing plaque on the lower back of a 10-year-old girl, whose appearance coincided with a recent diagnosis of Hashimoto's thyroiditis.
Semilocal Convergence for a Fifth‐Order Newton′s Method Using Recurrence Relations in Banach Spaces
Authors: Chen Liang , Gu Chuanqing , Ma Yanfang
Published: December 2011

We study a modified Newton′s method with fifth‐order convergence for nonlinear equations in Banach spaces. We make an attempt to establish the semilocal convergence of this method by using recurrence relations.
The recurrence relations for the method are derived, and then an existence‐uniqueness theorem is given to establish the
R‐order of the method to be five and a priori error bounds. Finally, a numerical application is presented to demonstrate
our approach.
Thyroid Cancer Incidence in New Jersey: Time Trend, Birth Cohort and Socioeconomic Status Analysis (1979–2006)
Authors: Roche Lisa M. , Niu Xiaoling , Pawlish Karen S. , Henry Kevin A.
Published: December 2011

The study's purpose was to investigate thyroid cancer incidence time trends, birth cohort effects, and association with socioeconomic status (SES) in New Jersey (NJ), a high incidence state, using NJ State Cancer Registry data. Thyroid cancer incidence rates in each sex, nearly all age groups, two major histologies and all stages significantly increased between 1979 and 2006. For each sex, age-specific incidence rates began greatly increasing in the 1924 birth cohort and, generally, the highest thyroid cancer incidence rate for each five-year age group occurred in the latest birth cohort and diagnosis period. Thyroid cancer incidence rates were significantly higher in NJ Census tracts with higher SES and in counties with a higher percentage of insured residents. These results support further investigation into the relationship between rising thyroid cancer incidence and increasing population exposure to medical (including diagnostic) radiation, as well as widespread use of more sensitive diagnostic techniques.
Accuracy of Fall Prediction in Parkinson Disease: Six-Month and 12-Month Prospective Analyses
Authors: Duncan Ryan P. , Leddy Abigail L. , Cavanaugh James T. , Dibble Leland E. , Ellis Terry D. , Ford Matthew P. , Foreman K. Bo , Earhart Gammon M.
Published: December 2011

Introduction. We analyzed the ability of four balance assessments to predict falls in people with Parkinson Disease (PD) prospectively over six and 12 months.Materials and Methods. The BESTest, Mini-BESTest, Functional Gait Assessment (FGA), and Berg Balance Scale (BBS) were administered to 80 participants with idiopathic PD at baseline. Falls were then tracked for 12 months. Ability of each test to predict falls at six and 12 months was assessed using ROC curves and likelihood ratios (LR).Results. Twenty-seven percent of the sample had fallen at six months, and 32% of the sample had fallen at 12 months. At six months, areas under the ROC curve (AUC) for the tests ranged from 0.8 (FGA) to 0.89 (BESTest) with LR+ of 3.4 (FGA) to 5.8 (BESTest). At 12 months, AUCs ranged from 0.68 (BESTest, BBS) to 0.77 (Mini-BESTest) with LR+ of 1.8 (BESTest) to 2.4 (BBS, FGA).Discussion. The various balance tests were effective in predicting falls at six months. All tests were relatively ineffective at 12 months.Conclusion. This pilot study suggests that people with PD should be assessed biannually for fall risk.
A Population-Based Study of Meconium Aspiration Syndrome in Neonates Born between 37 and 43 Weeks of Gestation
Authors: Fischer C. , Rybakowski C. , Ferdynus C. , Sagot P. , Gouyon J. B.
Published: December 2011

The epidemiology of meconium aspiration syndrome (MAS) in term neonates is described in a population-based retrospective study of data recorded for all births from 2000 to 2007 in a French region (Burgundy). Of the 132 884 eligible term newborns, the rate of meconium-stained amniotic fluid (MSAF) was 7.93%. The prevalence of severe MAS was 0.067% in the overall population. MAS rate was 0.11% at 37-38 weeks of gestation (WG), 0.20% at 39–41 WG, and 0.49% at 42-43 WG. Factors independently associated with severe MAS were identified by a case-control study, that is, thick meconium amniotic fluid, fetal tachycardia, Apgar score ≤3 at 1 minute, and birth in a level III facility. Our results confirm the high prevalence of MSAF after 37 WG but also show the low frequency of severe MAS in a period corresponding to the new international recommendations on the management of birth with MSAF.
Development of Class IIa Bacteriocins as Therapeutic Agents
Authors: Lohans Christopher T. , Vederas John C.
Published: December 2011

Class IIa bacteriocins have been primarily explored as natural food preservatives, but there is much interest in exploring the application of these peptides as therapeutic antimicrobial agents. Bacteriocins of this class possess antimicrobial activity against several important human pathogens. Therefore, the therapeutic development of these bacteriocins will be reviewed. Biological and chemical modifications to both stabilize and increase the potency of bacteriocins are discussed, as well as the optimization of their production and purification. The suitability of bacteriocins as pharmaceuticals is explored through determinations of cytotoxicity, effects on the natural microbiota, andin vivoefficacy in mouse models. Recent results suggest that class IIa bacteriocins show promise as a class of therapeutic agents.
Bacterial Artificial Chromosome Clones of Viruses Comprising the Towne Cytomegalovirus Vaccine
Authors: Cui Xiaohong , Adler Stuart P. , Davison Andrew J. , Smith Larry , Habib EL-Sayed E. , McVoy Michael A.
Published: December 2011

Bacterial artificial chromosome (BAC) clones have proven invaluable for genetic manipulation of herpesvirus genomes. BAC cloning can also be useful for capturing representative genomes that comprise a viral stock or mixture. The Towne live attenuated cytomegalovirus vaccine was developed in the 1970s by serial passage in cultured fibroblasts. Although its safety, immunogenicity, and efficacy have been evaluated in nearly a thousand human subjects, the vaccine itself has been little studied. Instead, genetic composition and in vitro growth properties have been inferred from studies of laboratory stocks that may not always accurately represent the viruses that comprise the vaccine. Here we describe the use of BAC cloning to define the genotypic and phenotypic properties of viruses from the Towne vaccine. Given the extensive safety history of the Towne vaccine, these BACs provide a logical starting point for the development of next-generation rationally engineered cytomegalovirus vaccines.
New Insights into the p38γ and p38δ MAPK Pathways
Authors: Risco Ana , Cuenda Ana
Published: December 2011

The mammalian p38 mitogen-activated protein kinases (MAPKs) family is composed of four members (p38α, p38β, p38γ, and p38δ), which are very similar in amino acid sequence but differ in their expression patterns. This suggests that they may have specific functions in different organs. In the last years most of the effort has been centred on the study of the function of the p38α isoform, which is widely referred to as p38 in the literature. However, the role that other p38 isoforms play in cellular functions and their implication in some of the pathological conditions have not been precisely defined so far. In this paper we highlight recent advances made in defining the functions of the two less studied alternative p38MAPKs, p38γ and p38δ. We describe that these p38MAPKs show similarities to the classical p38α isoform, although they may play central and distinct role in certain physiological and pathological processes.
Recent Advances on Filtering and Control for Nonlinear Stochastic Complex Systems with Incomplete Information: A Survey
Authors: Shen Bo , Wang Zidong , Liang Jinling , Liu Yurong
Published: December 2011

Some recent advances on the filtering and control problems for nonlinear stochastic complex systems with incomplete information are surveyed. The incomplete information under consideration mainly includes missing
measurements, randomly varying sensor delays, signal quantization, sensor saturations, and signal sampling. With such incomplete information, the developments on various filtering and control issues are reviewed in great detail. In particular, the addressed nonlinear stochastic complex systems are so comprehensive that they include conventional nonlinear stochastic systems, different kinds of complex networks, and a large class of sensor networks. The corresponding filtering and control technologies for such nonlinear stochastic complex systems are then discussed. Subsequently, some latest results on the filtering and control problems for the complex systems with incomplete information are given. Finally, conclusions are drawn and several possible future research directions are pointed out.
On the Convergence of Iterative Processes for Generalized Strongly Asymptotically ϕ‐Pseudocontractive Mappings in Banach Spaces
Authors: Colao Vittorio
Published: December 2011

We prove the equivalence and the strong convergence of iterative processes involving generalized strongly asymptotically ϕ‐pseudocontractive mappings in uniformly smooth Banach spaces.
Addiction and the Utilization of Medical Care
Authors: Lin Yen-Ju , Chen Chun-Chih , Liu Tsai-Ching , Lin Ying-Tzu
Published: December 2011

We investigate the effect of different scales of addictive factors on the utilization of medical services in this paper using a two-part model. Data are from the 2005 National Health Interview Survey and the claims data in the National Health Insurance Research Database in Taiwan. The results show that personal addictive behavior is significantly associated with both outpatient and inpatient utilization. Moreover, our result implies that those who smoked at least 20 cigarettes per day might not visit a doctor until the illness was severe. It suggests that the government can accomplish these goals by promotion and education in order to increase public awareness of personal health.