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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jbusres.2005.02.002 Byline: Franz T. Lohrke (a), Patrick M. Kreiser (b), K. Mark Weaver (c) Keywords: Alliances; Performance satisfaction; Behavioral theory of the firm; Threat rigidity Abstract: Although research has implicitly assumed small- or medium-sized enterprises (SMEs) employ alliances to improve performance, few studies have directly investigated how and when current performance levels might prompt firms to cooperate. Based on disparate predictions of the behavioral theory of the firm (BTOF) and threat rigidity thesis, we developed competing hypotheses regarding the impact of performance dissatisfaction on future alliance intentions for firms with and without previous alliance experience. Employing a dataset of 657 SMEs from six countries, results indicate that for firms with alliance experience, increasing managerial dissatisfaction with current performance decreased intentions to employ future alliances, thus supporting the BTOF thesis. Overall, these results highlight the importance that current performance satisfaction plays in influencing future alliance formation intentions. Author Affiliation: (a) Department of Management and Marketing, Culverhouse College of Commerce and Business Administration, University of Alabama, Box 870225 Tuscaloosa, AL 35487, United States (b) Department of Management Systems, College of Business, Ohio University, Athens, OH 45701, United States (c) College of Business, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States Article History: Received 9 September 2003; Accepted 1 February 2005 Article Note: (footnote) [star] Accepted for publication in Journal of Business Research (JBR), February 2005. An earlier version of this paper was presented at the Academy of Management meeting, Denver, CO, August 2002.

A meta-analysis is employed to examine extant research results for providing an insight into the relationship between firmEs slack resources and performance. Results provided evidence of a positive relationship among all three slack types, namely, available, recoverable, and potential and financial performance relationship than those not including these controls.

The fossil-rich Romualdo Formation (late Aptian/early Albian), Araripe Basin, northeastern Brazil, contains world-renowned Fossillagerstätten characterized by exceptionally preserved fossils. Macroinvertebrates in this formation are primarily represented by mollusks, echinoids, and decapod crustaceans. Mollusk shells are abundant in certain stratigraphic intervals, forming coquinas or shell pavements. Despite recent advances in our understanding of the taxonomy of certain groups, comprehensive taxonomic studies are lacking for almost the entire bivalve fauna. Therefore, a detailed taxonomic analysis is presented here. The described bivalves include four new genera (Araripenomia , Ciceromya , Inversatella , Australoeocallista), and six new species (Araripenomia infirma , Inversatella cearensis , Ciceromya edentulosa , Australoeocallista juazeiroi , Legumen kaririense , and Corbulomima delicata), in addition to Musculus maroimensis , Crassatella maroimensis , " Myrtea " sp. and " Tellina " sp. This bivalve fauna mainly consists of cosmopolitan and endemic brackish/marine genera, with Tethyan affinities. The fauna is not homogeneously distributed in the sedimentary succession of the Romualdo Formation, but is constrained to the third order highstand systems tract. Bivalves recorded from muddy facies are strongly dominated by infaunal and semi-infaunal suspension feeders. Assemblages of the sand-dominated facies, with dense shell accumulations of semi-infaunal to epifaunal byssate and infaunal suspension feeders, were formed under shallow, higher energy conditions. Despite the degree of generic endemicity, the mytilids, anomiids, crassateliids, astartids, tellinids, and corbulids are related to the bivalve fauna of the Early Cretaceous Riachuelo Formation of the Sergipe-Alagoas Basin, as previously demonstrated for the bakevelliids and echinoids. Indeed, the Romualdo bivalve fauna is, in part, a modified and impoverished brackish/marine fauna of the Riachuelo Formation. • Known for ∼180 years, the composition of the Early Cretaceous bivalve fauna of the Romualdo Formation is here unveiled. • Four new genera and six new species are described with the best possible anatomical accuracy. • Bivalve fauna closely resembles that of the Riachuelo Formation, Sergipe-Alagoas Basin, at the Brazilian continental margin. • Development of the bivalve fauna is closely related to sea level changes in an isolated interior, restricted marine basin. [ABSTRACT FROM AUTHOR]

The Lower Jurassic Mashabba Formation crops out in the core of the doubly plunging Al-Maghara anticline, North Sinai, Egypt. It represents a marine to terrestrial succession deposited within a rift basin associated with the opening of the Neotethys. Despite being one of the best and the only exposed Lower Jurassic strata in Egypt, its sedimentological and sequence stratigraphic framework has not been addressed yet. The formation is subdivided informally into a lower and upper member with different depositional settings and sequence stratigraphic framework. The sedimentary facies of the lower member include shallow-marine, fluvial, tidal flat and incised valley fill deposits. In contrast, the upper member consists of strata with limited lateral extension including fossiliferous lagoonal limestones alternating with burrowed deltaic sandstones. The lower member contains three incomplete sequences (SQ1-SQ3). The depositional framework shows transgressive middle shoreface to offshore transition deposits sharply overlain by forced regressive upper shoreface sandstones (SQ1), lowstand fluvial to transgressive tidal flat and shallow subtidal sandy limestones (SQ2), and lowstand to transgressive incised valley fills and shallow subtidal sandy limestones (SQ3). In contrast, the upper member consists of eight coarsening-up depositional cycles bounded by marine flooding surfaces. The cycles are classified as carbonate-dominated, siliciclastic-dominated, and mixed siliciclastic-carbonate. The strata record rapid changes in accommodation space. The unpredictable facies stacking pattern, the remarkable rapid facies changes, and chaotic stratigraphic architecture suggest an interplay between allogenic and autogenic processes. Particularly syndepositional tectonic pulses and occasional eustatic sea-level changes controlled the rate and trends of accommodation space, the shoreline morphology, the amount and direction of siliciclastic sediment input and rapid switching and abandonment of delta systems. [ABSTRACT FROM AUTHOR]

Middle to Late Jurassic belemnites from the Spiti and Zanskar valleys in the Indian Himalayas were used for stable isotope (δ13C, δ18O) and element (Mg/Ca, Sr/Ca) analyses. Although the Himalayan orogeny deformed and altered a large portion of the collected fossils, cathodoluminescence and scanning electron microscopy in combination with analyses of iron and manganese contents allowed the identification of belemnites believed to still retain their original chemical composition. Results indicate a long-term temperature decrease from the Middle Callovian–Oxfordian to the Tithonian, which is proposed to have been caused by a concomitant drift of eastern Gondwana into higher palaeolatitudes. Reconstructed absolute temperatures depend on the used equation and assumed δ18O value of seawater, but most likely varied between 17.6 °C to 27.6 °C in the Kimmeridgian and Tithonian with average values between 22 °C to 24 °C. This way, temperatures were similar to slightly warmer than today at comparable latitudes. The reconstruction of absolute temperatures for the Middle Callovian–Oxfordian was hindered by a larger number of poorly preserved belemnites representing this time interval. [ABSTRACT FROM AUTHOR]

The known occurrences of Early Cretaceous freshwater bivalves in the Araripe Basin are confined to the 0.85- to 2-m-thick Caldas Bed of the Crato Formation. Herein, we record a new bivalve-dominated assemblage in a siltstone bed nearly 30 m below the upper boundary with the overlying Romualdo Formation. The assemblage is composed of ecologically incompatible bivalve mollusk species, being dominated by tiny individuals of Modiolus ? sp., a brackish water form. These are directly associated with the freshwater bivalves Araripenaia elliptica and Monginellopsis bellaradiata , the latter two species commonly found in the Caldas Bed. Those bivalves are mixed with carbonized, partially comminuted plant remains. Specimens of Modiolus ? sp. are usually articulated and are dispersed to loosely packed or forming cm-long clusters. A few shells of the freshwater forms are also articulated. The bivalves lived in a semi-confined embayment setting with fluctuating salinity. Background brackish water conditions must have existed long enough for the Modiolus ? sp. larvae to settle and develop as juvenile individuals. Rapid salinity fluctuations associated with sea level and climate variations allowed A. elliptica and M. bell aradiata to thrive in the same area. Hence, the numerically dominant shells of the brackish water forms and the freshwater bivalves have been telescoped into the same bedding plane, generating an environmentally condensed, time-averaged benthic assemblage. Finally, the presence of these taxa considerably expands the vertical/temporal distribution of bivalve mollusks within the Crato Formation. • New environmentally condensed, bivalve-dominated assemblage from the Crato Formation. • Ecologically incompatible bivalve taxa lived asynchronously in a semi-confined bay. • Brackish and freshwater mollusks in a single bedding plane of Crato Formation. • Bivalve mollusks in rocks other than the fossil-rich limestones and the Caldas Bed. [ABSTRACT FROM AUTHOR]

Abstract The Cretaceous (upper Aptian) Romualdo Formation of the Araripe Basin, northeastern Brazil, is a marine-influenced, predominantly fine-grained siliciclastic unit. In the eastern part of the basin, it corresponds to a depositional sequence composed of two transgressive-regressive cycles. Low-diversity benthic macrofaunas document high-stress conditions. Their palaeoecological and taphonomic analysis allows for the detailed reconstruction of the palaeoenvironments and of the temporal changes in the palaeoecosystem. The transgressive part of the lower cycle is a black shale with calcareous concretions that contain excellently preserved fishes and other vertebrates (the famous "Santana fossils"), but apart from abundant ostracods and rare decapod crustaceans, benthic faunal elements are very rare due to anoxic to dysoxic conditions. A low-diversity parautochthonous molluscan fauna of small bivalves and gastropods records fluctuating dysoxic conditions during early regression. Towards the top of the measured sections (late regression), thin gastropod shell beds become conspicuous. At the top of the sections decimetre-thick shell concentrations show signs of reworking and a greater marine influence (transgressive part of the upper cycle). The distribution pattern of three benthic associations and two assemblages is almost equally shaped by three environmental parameters: The low overall species diversity, small size of the fauna, and the lack of stenohaline elements suggest lowered and fluctuating salinity conditions. Fluctuating redox conditions with anoxia to dysoxia, identified especially in the lower parts of the succession, and substrate were the other two factors shaping the faunal distribution. The late Aptian sedimentary and faunal history of the eastern part of the basin indicates restricted marine influence, coupled with increasing freshwater input during phases of sea-level lowstand, and low-energy conditions offshore, which led to widespread anoxia, especially in the lower part of the formation. Thus, palaeoecological analyses are an excellent tool to disentangle the various environmental parameters that shaped the palaeoenvironments of the basin, to understand more closely its Fossil-Lagerstätten , and to corroborate and fine-tune the sequence stratigraphic framework. [ABSTRACT FROM AUTHOR]

Abstract Recent preclinical trials have shown that alginate injections are a promising treatment for ischemic heart disease. Although improvements in heart function and global structure have been reported following alginate implants, the underlying structure is poorly understood. Using high resolution ex vivo MRI and DT-MRI of the hearts of normal control swine (n = 8), swine with induced heart failure (n = 5), and swine with heart failure and alginate injection treatment (n = 6), we visualized and quantified the fibre distribution and implant material geometry. Our findings show that the alginate injectates form solid ellipsoids with a retention rate of 68.7% ± 21.3% (mean ± SD) and a sphericity index of 0.37 ± 0.03. These ellipsoidal shapes solidified predominantly at the mid-wall position with an inclination of −4.9° ± 31.4° relative to the local circumferential direction. Overall, the change to left ventricular wall thickness and myofiber orientation was minor and was associated with heart failure and not the presence of injectates. These results show that alginate injectates conform to the pre-existing tissue structure, likely expanding along directions of least resistance as mass is added to the injection sites. The alginate displaces the myocardial tissue predominantly in the longitudinal direction, causing minimal disruption to the surrounding myofiber orientations. [ABSTRACT FROM AUTHOR]

Modeling details of frequency dependent parameters and a method for taking those into account in time domain high frequency (HF) transformer simulations are presented. Frequency dependent turn resistance and core losses are considered. The suggested method is general and thus not limited only to the considered frequency dependent parameters. Frequency dependent turn resistance and core losses are obtained by performing frequency domain (FD) finite element method (FEM) simulations. The obtained frequency dependences are approximated by a set of functions with existing Inverse Fourier Transform (IFT) and used in convolution integrals of the time domain model of a transformer winding system. The obtained simulation results are verified by comparison against measurements. [ABSTRACT FROM AUTHOR]

[Display omitted] • First absolute seawater temperatures for the Jurassic of Iran are estimated. • Oxygen isotope analyses of calcitic fossils indicate a significant long-term warming. • Warming is explained by plate tectonic shift of Central Iran into lower latitudes. • Warming also caused changes in sedimentation and ecosystem composition. • Plate tectonics drive regional long-term climate patterns in the Middle-Late Jurassic. Stable oxygen isotope values of calcitic marine fossils (δ18O shell) were used to calculate the first absolute seawater temperature estimates for the Jurassic of Central Iran. Results indicate a significant long-term warming in the study area through the Middle to Late Jurassic of around 6 °C or more (0.3 to 0.4 °C per million years). Following recent methodological advances in temperature reconstructions, the δ18O shell values of bivalves translate into water temperatures slightly warmer than in today's oceans at comparable latitudes with averages of 26.6 °C in the Middle Jurassic and 32.1 °C in the Late Jurassic. Belemnites would indicate still warmer temperatures, but these values might be less reliable and partly overestimated due to potentially altered specimens. The recorded long-term warming can be explained by a concurrent major plate tectonic shift of Central Iran from temperate to tropical latitudes. The gradual influence of this southward drift is also seen by changes in sedimentation and ecosystem composition. This way, the stable oxygen isotope record of Central Iran is further evidence for the strong impact of plate tectonics on regional long-term climate patterns in the Middle and Late Jurassic. [ABSTRACT FROM AUTHOR]

Abstract: Fossils from the “Jehol Biota” have been studied for nearly 90 years, and the term “Jehol Biota” has been extensively used and is well known today, largely thanks to the discovery of feathered dinosaurs, angiosperms, and numerous other exceptionally preserved fossils in the Lower Cretaceous of northeastern China. Ironically, however, what exactly the Jehol Biota represents and how it is defined has hardly been discussed. The lack of a precise definition of the Jehol Biota has hindered our understanding of such important issues as its palaeodiversity, its spatial and temporal distribution, and the pattern of radiation of the biota. In this paper, we propose that the Jehol Biota is defined by using a palaeoecological concept, and by combining ecological and taphonomic aspects, i.e., as organisms that lived in the Early Cretaceous volcanic-influenced environments of northeastern China, and were buried in lacustrine and rarely fluvial sediments, where most turned into exceptionally preserved fossils. The relationship between the Jehol Biota and the Jehol Group is also clarified. According to the revised definition, the Jehol Biota is so far only discovered in deposits of the Yixian and Jiufotang formations of western Liaoning, adjacent Inner Mongolia, and northern Hebei, and the Huajiying Formation of northern Hebei. Temporally it ranges from the Barremian to Aptian, i.e., for at least 10 Ma (130–120 Ma). [Copyright &y& Elsevier]

Abstract: The study combines the results of stable isotope (δ 13C, δ 18O) analyses of 187 belemnites, brachiopods, and oysters from the Middle to Upper Jurassic (Upper Callovian to Kimmeridgian) of the Kachchh Basin in western India. Generally, belemnites show lower δ 13C and higher δ 18O ratios than the benthic fauna. It is proposed that this discrepancy is caused by different life habitats of both groups with belemnites spending major parts of their life in deeper water outside the Kachchh Basin and entering shallow areas only occasionally (e.g., during seasonal migrations to spawning grounds). A mode of life as fast-swimming, nektonic predators similar to many modern squid species seems plausible. The study emphasises that results of stable isotope analyses should be evaluated separately for each fossil group. In addition to the influence of diagenetic alteration, weathering, salinity changes, and sea-level fluctuations, the ecology of the analysed fossil taxa has to be considered. Temperatures calculated from δ 18O ratios point to relatively warm conditions around the Middle to Late Jurassic transition with no evidence for a glacial phase which had been proposed for this boundary. A distinct fall in temperatures is observed during the Middle Oxfordian reaching a minimum in the early Late Oxfordian. It is tempting to connect this event with the break-up of Gondwana causing stronger upwelling in the northwestern Tethys or alternatively the influx of polar water by the opening of the Transgondwanan Seaway. However, such connections cannot be verified without further data, preferably from localities in the southern Malagasy Gulf (e.g., Madagascar) and from younger horizons (Kimmeridgian–Tithonian). [Copyright &y& Elsevier]

Abstract: The Upper Callovian-Oxfordian strata of the Kachchh Basin, western India, record three positive excursions of phosphorus. They have been documented in three sections of the Chari Formation from different parts of the basin. Corroboration of field and petrographic data with trends of major and trace elemental data and elemental ratios of the strata revealed that these excursions were coeval with reduced chemical weathering in the source area and significant reduction of siliciclastic influx to the depositional sites. The study also revealed the intrabasinal source of P, and minor sea-level fluctuations and resultant episodic sediment recycling as the causative factors. Considering the geographic locations of the three sections, the phosphorus anomalies seem to be controlled by a regional and/or basin-scale process, if not linked with global signals. Temporal resolution of these anomalies suggests that the processes were episodic and related to short term climate/relative sea-level cycles, the durations of which could be unraveled with high-resolution biostratigraphic data. [Copyright &y& Elsevier]

Purpose: For nonsurgical treatment of fractures of the proximal phalanges of the triphalangeal fingers, different dynamic casts have been described. The main principle behind these casts is advancement and tightening of the extensor hood, caused by a combination of blocking the metacarpophalangeal joints in flexion and actively flexing the proximal interphalangeal joints. In contrast to established treatment protocols using functional forearm casts, the Lucerne cast allows for free mobilization of the wrist joint. The purpose of the current multicenter study was to compare the results of conservative, functional treatment using 2 different methods, either a forearm cast or a Lucerne cast. Methods: Over a 2-year-period, a prospective, randomized, multicenter study was conducted at 4 hospitals in Switzerland. Clinical and radiological results of 66 consecutive patients having 75 extra-articular fractures of the proximal phalanges were recorded through a minimum follow-up of 3 months. Intra-articular and physeal fractures, pathological fractures, open fractures, concomitant injuries of the tendons or collateral ligaments, and accidents more than 7 days before presentation were excluded from the study. Results: Radiographically, there were no statistically significant differences between the 2 groups in terms of palmar apex angulation and radial or ulnar angulation. There were no differences in total active range of finger motion. Wrist joint motion at the time of cast removal was statistically superior in patients treated with Lucerne cast. However, there were no significant differences in wrist joint motion at 12 weeks of follow-up. Conclusions: The clinical and radiological results achieved with the Lucerne cast are comparable to those of established treatment. Well-reduced, minimally angulated, or nonangulated fractures of the proximal phalanges of the fingers can be effectively treated using functional casts without immobilizing the wrist. Type of study/level of evidence: Therapeutic II. [Copyright &y& Elsevier]

Abstract: Thermoplastic polyurethanes are used in a variety of medical devices and experimental tissue engineering scaffolds. Despite advances in polymer composition to improve their stability, the correct balance between chemical and mechanical properties is not always achieved. A model compound (MC) simulating the structure of a widely used medical polyurethane (Pellethane®) was synthesized and reacted with aliphatic and olefinic acyl chlorides to study the reaction site and conditions. After adopting the conditions to the olefinic modification of Pellethane®, processing into flat sheets, and crosslinking by thermal initiation or ultraviolet radiation, mechanical properties were determined. The modified polyurethane was additionally electrospun under ultraviolet light to produce a crosslinked tubular vascular graft prototype. Model compound studies showed reaction at the carbamide nitrogen, and the modification of Pellethane with pentenoyl chloride could be accurately controlled to up to 20% (correlation: ρ =0.99). Successful crosslinking was confirmed by insolubility of the materials. Initiator concentrations were optimized and the crosslink densities shown to increase with increasing modification. Crosslinking of Pellethane containing an increasing number of pentenoyl groups resulted in decreases (up to 42%, p <0.01) in the hysteresis and 44% in creep (p <0.05), and in a significant improvement in degradation resistance in vitro. Modified Pellethane was successfully electrospun into tubular grafts and crosslinked using UV irradiation during and after spinning to render them insoluble. Prototype grafts had sufficient burst pressure (>550mmHg), and compliances of 12.1±0.8 and 6.2±0.3%/100mmHg for uncrosslinked and crosslinked samples, respectively. It is concluded that the viscoelastic properties of a standard thermoplastic polyurethane can be improved by modification and subsequent crosslinking, and that the modified material may be electrospun and initiated to yield crosslinked scaffolds. Such materials hold promise for the production of vascular and other porous scaffolds, where decreased hysteresis and creep may be required to prevent aneurismal dilation. [Copyright &y& Elsevier]

Abstract: A Turonian ammonite faunule from the Shotori Mountains (east-central Iran) with Thomasites koulabicus (Kler) and Collignoniceras woollgari regulare (Haas) is recorded for the first time and briefly described. Thomasites koulabicus appears, in contrast to the widely distributed C. w. regulare, to be restricted to central East Asia. Its occurrence in east-central Iran provides new insights into the Turonian ammonite palaeobiogeography of the area. The ammonites document a Cretaceous marine transgression onto the Shotori Mountains in the central part of the Central-East Iranian Microcontinent during the Early–Middle Turonian. The nearshore character of the host sediments, a strong terrigenous input, and the intercalation of conglomerates originating from nearby cliffs suggest that at least portions of the Shotori Mountains defied inundation by the Turonian sea. This “Shotori Island” was surrounded by shelf seas and narrow oceanic basins, forming an important palaeogeographical feature in the Tethysides of the Middle East during the Late Cretaceous. [Copyright &y& Elsevier]

In this paper, the stratigraphy and depositional setting of Upper Jurassic basinal sediments at the eastern margin of the Tabas Block of east-central Iran are discussed with special emphasis on the rich ammonite fauna. The basinal sediments comprise the upper part of the Qal’eh Dokhtar Limestone Formation and a new, hitherto not recognized lithostratigraphic unit, the low-weathering Korond Formation, which is formally introduced herein. The recognition of the Korond Formation requires significant changes in the geological maps of the area, because invariably, it has been mapped as the Middle Jurassic Baghamshah Formation. As a result, several large faults become superfluous and the tectonic structure of the area is far simpler than hitherto assumed. The upper Qal’eh Dokhtar Limestone and the Korond formations formed in a lower slope-to-basin environment to the east of a huge, N/S trending carbonate platform (represented by the Esfandiar Limestone Formation) fringing the eastern margin of the Tabas Block. The spread of the basinal Korond Formation onto the eastern occurrences of the Esfandiar Platform in the Late Oxfordian to Early Kimmeridgian indicates a partial drowning of this platform. Most of the described ammonites come either from the condensed drowning unconformity at the top of the Esfandiar Limestone Formation or from the upper 100 m of the Qal’eh Dokhtar Limestone Formation. The ammonite fauna is dominated by perisphinctids and phylloceratids and indicates a Middle to early Late Oxfordian age for the top of the Qal’eh Dokhtar Limestone Formation and a Late Oxfordian to late Early Kimmeridgian age for the Korond Formation. A systematic description of the ammonite fauna is presented. [Copyright &y& Elsevier]

The work described herein focuses on the effect a change in the laminate stacking sequence has on the ability to dissipate kinetic projectile energy. Two different T800 carbon fibre filament wound tubes in an epoxy matrix with lay-ups of [−35°/+35°/90°3/−35°/+35°/90°3/−35°/+35°] (laminate A) and [90°6/(−35°/+35°)3] (laminate B) are investigated. The tubes are subjected to impacts up to and above the ballistic limits. The energy dissipated by material failure and friction is quantified and shown to be similar for the two laminates at the respective ballistic limits. The results indicate that laminate B provides the best energy dissipation performance as a result of a higher ballistic limit than laminate A and a difference in the strain energy due to a different local response of the two laminates. [Copyright &y& Elsevier]

This paper presents an experimental investigation into the response of glassfibre chopped-strand mat laminates to air pressure blasts. Experiments were conducted with a variety of monolithic and layered targets of laminates with differing areal densities. Results of the post-impact visual inspection show three distinct damage modes: matrix cracking, delamination/debonding, and penetration as final damage. The analysis focuses on resistance to damage of these modes, damage propagation with increasing blast impulse, damage distribution in the thickness direction of the targets, and the influence of blast attenuation and large-area support on the target response. [Copyright &y& Elsevier]

The fossil-rich carbonate deposits of the Aptian Crato Formation, Araripe Basin (Brazil) are one of the main Cretaceous Konservat-Lagerstätten of Gondwana, and have come to fame globally. However, information on fossils from deposits other than the famous laminites of the basal part of the unit is scarce. Herein, we describe the first bivalves of the suborder Silesunionidina Skawina and Dzik, 2011 in the order Unionida Gray, 1854 from South America. The specimens were collected from a 0.3–1-m-thick grey to yellow mudstone interval located 0.3 m above the laminated limestones of the lower part of the Crato Formation at Nova Olinda, State of Ceará. They comprise exquisite composite, internal and external moulds, preserving key anatomical characters. Based on the analysis of muscle scars, hinge and ornamentation, these bivalves are here assigned to a new genus and species, Cratonaia novaolindensis gen. et sp. nov. The presence of a series of small pedal elevator scars linearly arranged on the external wall of the umbonal cavity indicates that this is a member of the suborder Silesunionidina. The new form is the by far youngest representative of this group. Closely related bivalves were previously reported from Triassic deposits of Australia, Africa, Europe and potentially India. Detailed stratigraphic, sedimentological and taphonomic observations indicate that the new taxon thrived in a freshwater lake. The occurrence of Silesunionoidea in the Lower Cretaceous of South America indicates that the condition of the musculature in Mesozoic freshwater mussels needs to be established to assign them confidently at family level. • Unionida bivalve Cratonaia novaolindensis gen. et sp. nov. described from NE Brazil. • First record of Silesunionidina bivalves in South America. • Youngest known Silesunionidina bivalve by far. • A long phase of parallel evolution between silesunionoids and unionoids is suggested. • Family/superfamily assignment of Mesozoic freshwater mussels in general is dependent on the condition of their musculature. [ABSTRACT FROM AUTHOR]

The stable isotope (δ13C, δ18O) composition of a collection of Lower Jurassic brachiopods and oysters from the Andean Basin of northern Chile was analyzed. The results allow the first reconstruction of absolute water temperatures for several ammonite zones in the Lower Jurassic of South America. The temperature record starts with comparatively high values in the Late Sinemurian (average: 27.0 °C; Raricostatum Zone). Just before the Sinemurian–Pliensbachian transition, temperatures dropped to an average of 24.3 °C. The lowest temperature value in the dataset was recorded for a brachiopod shell of the latest Pliensbachian Spinatum Zone (19.6 °C). No data are available for the Early Toarcian, but results for the late Toarcian show again comparatively warm conditions (average: 24.4 °C; Thouarsense–Levesquei zones). Even though more material and analyses are necessary to corroborate the recorded temperatures, the present dataset seems to indicate the global nature of the Late Pliensbachian Cooling Event. In contrast, the global warming during the Toarcian Oceanic Anoxic Event has not been recorded due to a lack of Early Toarcian material. The δ13C record of brachiopods and oysters documents a gradual increase in values representing background conditions. Oyster shells were used for high-resolution stable isotope analyses and show seasonal temperature fluctuations over a period of around 3 years in the life time of the bivalves. If explained only by temperatures, the δ18O values point to a minimum estimate for the seasonality in the late Toarcian of slightly more than 3 °C. [ABSTRACT FROM AUTHOR]

Background & Aims Polycystic liver disease (PLD), the most common extrarenal manifestation of autosomal-dominant polycystic kidney disease (ADPKD), has become more prevalent as a result of increased life expectancy, improved renal survival, reduced cardiovascular mortality, and renal replacement therapy. No studies have fully characterized PLD in large cohorts. We investigated whether liver and cyst volumes are associated with volume of the hepatic parenchyma, results from liver laboratory tests, and patient-reported outcomes. Methods We performed a cross-sectional analysis of baseline liver volumes, measured by magnetic resonance imaging, and their association with demographics, results from liver laboratory and other tests, and quality of life. The data were collected from a randomized, placebo-controlled trial underway at 7 tertiary-care medical centers to determine whether the combination of an angiotensin I–converting enzyme inhibitor and angiotensin II–receptor blocker was superior to the inhibitor alone, and whether low blood pressure (<110/75 mm Hg) was superior to standard blood pressure (120–130/70–80 mm Hg), in delaying renal cystic progression in 558 patients with ADPKD, stages 1 and 2 chronic kidney disease, and hypertension (age, 15–49 y). Results We found hepatomegaly to be common among patients with ADPKD. Cysts and parenchyma contributed to hepatomegaly. Cysts were more common and liver and cyst volumes were greater in women, increasing with age. Patients with advanced disease had a relative loss of liver parenchyma. We observed small abnormalities in results from liver laboratory tests, and that splenomegaly and hypersplenism were associated with PLD severity. Higher liver volumes were associated with a lower quality of life. Conclusions Hepatomegaly is common even in early stage ADPKD and is not accounted for by cysts alone. Parenchymal volumes were larger, compared with liver volumes of patients without ADPKD or with those predicted by standardized equations, even among patients without cysts. The severity of PLD was associated with altered biochemical and hematologic features, as well as quality of life. ClinicalTrials.gov identifier: NCT00283686 . [ABSTRACT FROM AUTHOR]

Abstract: We examined six patients with isolated venous thrombosis (n =2), or venous thrombosis combined with sinus thrombosis (n =4) (CVT). The clinical symptoms were non-specific (acute cephalea, paresis, epileptic seizure, progressive speech disorder). All examinations were performed on a 1.5 T system (Magnetom Symphony, Siemens, Erlangen, Germany), maximum gradient field strenght 30mT/m, minimal gradient rise time 450μs, according to the following protocol: Transverse T2-weighted turbo spin-echo (TSE), fluid attenuated inversion recovery (FLAIR), T1-weighted spin-echo (SE), before and after administration of contrast medium, T2*-weighted conventional gradient-echo (GRE), T2*-weighted spin-echo echo planar imaging (SE EPI), both without and with diffusion weighting as well as two-dimensional (2D) venous time-of-flight (TOF) MRA. The venous thromboses were best detectable in the T2*-weighted conventional GRE sequence in all patients. In two patients, the CVT was discernible only in this sequence. The sinus thrombosis was well discernible only in the T2*-weighted GRE sequence in only one case; in the remaining cases it was detectable only with difficulty. For these cases, other sequences such as SE, diffusion-weighted, or 2D-TOF-MRA sequence were superior. The T2*-weighted conventional GRE sequence was superior to the T2*-weighted SE EPI sequence in all patients. To sum up, it can be concluded, that T2*-weighted conventional GRE sequences are possibly the best method of detection of acute cortical vein thromboses. Therefore, it seems to be of benefit to integrate a T2*-weighted conventional GRE sequence into the MR-protocol for the diagnosis of isolated cortical vein thrombosis. [Copyright &y& Elsevier]