Fixation Period Research Articles

How Do Banks and Households Manage Interest Rate Risk? Evidence from the Swiss Mortgage Market

We exploit a unique data set that features both un-intermediated mortgage requests and independent offers from multiple banks for each request. We show that households typically are not prudent risk managers but prioritize the minimization of current mortgage payments over the risk of possible hikes in future mortgage payments. We also provide evidence that banks do influence the contracted mortgage rate fixation periods, trading off their own exposure to interest rate risk against the borrowers’ affordability and credit risk. Our results challenge the implicit assumption of the existing mortgage choice literature whereby fixation periods are determined entirely by households.

Why the item will remain the unit of attentional selection in visual search.

Hulleman & Olivers (H&O) reject item-based serial models of visual search, and they suggest that items are processed equally and globally during each fixation period. However, neuroscientific studies have shown that attentional biases can emerge in parallel but in a spatially selective item-based fashion. Even within a parallel architecture for visual search, the item remains the critical unit of selection.

Surgical treatment of condylar head fractures, the way to minimize the postraumatic TMJ ankylosis.

Management of condylar head fractures (CHF) of the temporomandibular joint (TMJ) remains a source of controversy. Based on established literature, group of CHFs and conservative treatment connected with period of maxillomandibular fixation (MMF) increases the risk for TMJ ankylosis. This paper presents anatomical and functional results of surgical treatment of condylar head fractures in a group of 24 patients (29 joints). Fractures were diagnosed based on conventional radiographs and computed tomography (CT) scans. Utilising an intraoperative arthroscopy authors evaluated actual intraarticular posttraumatic changes. This study presents acceptable functional and radiological results of surgical treatment of condylar head fractures with more than 3-year follow-up. The authors believe that re-establishing the pretraumatic anatomic position of the TMJ components (fragment and the disc) and early postoperative rehabilitation are inevitable to minimize the risk of postraumatic TMJ ankylosis (Tab. 2, Fig. 8, Ref. 31).

Shear bond strength of brackets bonded with nanofilled flowable resins

Introduction and Objective: To evaluate the shear bond strength of brackets fixed with different materials (two light-cured nanofilled low-viscosity resins –Transbond Supreme LV and Flow Tain LV and two light-cured traditional resins – Transbond XT and Transbond Plus Color Change) after 10 min and 24 h, and to evaluate the type of failure. Material and methods: Eighty bovine incisors were selected and randomly divided into groups (n = 10) according to the material and fixation period. The brackets were bonded following the manufacturer's instructions and stored in deionized water at 37 oC for 10 min or 24 h. After, the specimens were submitted to shear bond strength test at 0.5 mm/min and evaluated for adhesive remnant index (ARI). The data were submitted to Kruskal Wallis and Wilcoxon tests (p < 0.05) and the ARI scores to Chi-Square test. Results: There was a significant difference among the materials (p < 0.05 (after 10 min – Transbond XT > Transbond Plus Color Change > Transbond upreme LV = Flow Tain LV and after 24 h – Transbond XT > Transbond Plus Color Change = Transbond Supreme LV = Flow Tain LV). There was osignificant difference in resistance values between 10 min and 24 h, except for Transbond Plus Color Change. Most groups showed adhesive remaining adhered to the enamel (scores 2 and 3) without statistical significant difference (p > 0.05). Conclusion: The light-cured traditional resins showed higher resistance than the nanofilled materials. The period of fixation had no influence on the resistance for different materials, except for Transbond Plus Color Change.

Unilateral spinal anesthesia : Literature review and recommendations

Unilateral spinal anesthesia is acost-effective and rapidly performed anesthetic technique. An exclusively unilateral block only affects the sensory, motor and sympathetic functions on one side of the body and offers the advantages of aspinal block without the typical adverse side effects seen with abilateral block. The lack of hypotension, in particular, makes unilateral spinal anesthesia suitable for patients with cardiovascular risk factors e. g. aortic valve stenosis or coronary artery disease. Increasing numbers of surgical procedures are now being performed on an outpatient basis. Until now, spinal anesthesia has been considered unsuitable for this, not only because of the high incidence of intraoperative hypotension and postoperative urinary retention but also because of the prolonged postoperative stay before home discharge. This is not the case with unilateral spinal anesthesia: motor function returns rapidly, the incidence of urinary retention is extremely low, and patients are usually eligible for home discharge sooner than after bilateral spinal anesthesia or general anesthesia. The success of the technique depends on anumber of factors. In addition to the local anesthetic, its concentration and dose, and the baricity of the injected solution, the shape of the spinal needle, the injection speed, the patient'sposition during injection, and the time the patient remains in this position after injection are equally important parameters. Anumber of intrathecally applied adjuvant drugs are used to give amore intense and/or longer-lasting block. For this review, we collated the published data on unilateral spinal anesthesia from journals with an impact factor greater than 1.0 and defined an optimized method for performing the technique. In order to achieve an exclusively unilateral block one should use 0.5 % hyperbaric bupivacaine injected at arate of 0.33ml/min or slower. During the injection and the following 20min the patient should lie in the lateral decubitus position on the side intended for surgery with knees drawn to the chest. An injection of 5mg (1ml) hyperbaric bupivacaine 0.5 % provides an hour-long block to T12, and adose of 7.5 to 10mg (1.5-2.0ml) extends the block to T6. Adding clonidine (0.5 to 1.0µg/kg BW) to the injection prolongs the duration of the block to approximately two to three hours. During the 20-minute fixation period, the cephalad spread of the block can be influenced to acertain extent by raising or lowering the head of the table.

Cerebellar output encodes a corrective saccadic command (Commentary on Sun et al.).

Cerebellar output encodes a corrective saccadic command (Commentary on Sun et al.).

The effect of an interfragmentary gap on the clinical outcome after mandibular angle fracture surgery

The mandibular angle fracture occasionally widens at the lower border after surgery using a single miniplate. However, the effects of an interfragmentary gap have not been fully investigated. The aim of this study was to determine the effects of gaps caused by mandibular angle fracture surgery using a single superior border miniplate technique. In this prospective study, the interfragmentary gap was measured by panoramic radiography and cone-beam computed tomography (CBCT) postoperatively. The width of the gap measured by panoramic radiography and CBCT scans was compared. The patients were divided into two groups based on the gap width (more or less than 1.5 mm). In CBCT scans, bucco-lingual displacement of the proximal segment was evaluated. Clinical results and complication rates were investigated according to the gap and displacement. The findings were statistically analyzed. Thirty-two patients were included in the study. The mean interfragmentary gap widths were 1.56 ± 0.83 mm by panoramic radiography and 2.12 ± 0.87 mm by CBCT scans. CBCT measured a gap width of approximately 0.5 mm wider than panoramic radiography (P = 0.001). Twenty-two patients (68.8%) had an interfragmentary gap width of >1.5 mm, and ten patients (31.2%) had a gap width of <1.5 mm. All patients had favorable occlusion at the last clinical examination. There were no statistically significant differences in intermaxillary fixation periods and complication rates (P > 0.05). One patient in the wider gap group experienced pain in the temporomandibular joint when opening the mouth. Six patients (18.8%) had lingual displacement of the proximal fragment. Displacement did not significantly influence the complication rate (P > 0.05). The presence of an interfragmentary gap after mandibular angle fracture surgery did not affect the clinical outcome.

Stability of human binocular alignment in the dark and under conditions of nonfixation

To evaluate the stability of human binocular alignment under conditions of altered fixation and luminance. Horizontal binocular alignment in 8 healthy orthotropic subjects was measured using infrared video-oculography (VOG) under conditions of binocular fixation and luminance change. Each testing condition was preceded by a binocular fixation period in room light (475 lux) to define the baseline binocular alignment. Binocular alignment was then measured in darkness without fixation, in room light through a semitranslucent filter that precluded fixation, and in darkness with a distant fixational target. We used the signed rank test to determine statistically whether these experimental conditions induced significant binocular alignment change from each baseline binocular alignment. The mean horizontal binocular alignment in the dark without fixation was similar to baseline binocular alignment (0.2°±2.8°; P=0.4). The mean horizontal binocular alignment without fixation in room light was also similar to baseline binocular alignment (-1.4°±1.6°; P=0.08). The mean horizontal binocular alignment in the dark when a fixational target was provided showed an exodrift compared to baseline alignment (2.3°±1.0°; P=0.0004). The human brain does not require visual input to maintain binocular alignment on a short-term basis. The resilience of binocular alignment probably reflects the presence of phoria adaptation.

Management of tibial diaphyseal fractures with linear external skeletal fixators using carbon connecting rods in dogs

Dogs (12) with unstable tibial diaphyseal fractures, selected for this study, were stabilized with bilateral uniplanar Type II external skeletal fixators using stainless steel positive profile centrally threaded transfixation full pins, 2- way AO clamps and indigenously designed carbon fiber rods. Clinical lameness evaluation and radiographic evaluation for fixator stability, fragment alignment and callus formation were studied. Post-operatively, no breakage or bending of the carbon fiber rods was seen throughout the fixation period. Fixator staged disassembly and complete removal was done on an average 4–9 weeks in all cases which showed grade I lameness after removal. Complications like pin tract infection, wound at suture site due to wound dehiscence and wound at pin-skin interface were seen, which subsided later without any affect on bone healing. Lameness grading, pain score and radiographic evaluation of healing were estimated in all the cases throughout the fixation period. ESF using carbon fiber connecting rod appears as a practicable method for repair of tibial diaphyseal fractures with minimum risk of fixator destabilization. Fixator staged disassembly at 4 weeks accelerated bone healing and promoted earlier limb function.

Eye movements between saccades: Measuring ocular drift and tremor

Intersaccadic periods of fixation are characterized by incessant retinal motion due to small eye movements. While these movements are often disregarded as noise, the temporal modulations they introduce to retinal receptors are significant. However, analysis of these input modulations is challenging because the intersaccadic eye motion is close to the resolution limits of most eyetrackers, including widespread pupil-based video systems. Here, we analyzed in depth the limits of two high-precision eyetrackers, the Dual-Purkinje Image and the scleral search coil, and compared the intersaccadic eye movements of humans to those of a non-human primate. By means of a model eye we determined that the resolution of both techniques is sufficient to reliably measure intersaccadic ocular activity up to approximately 80Hz. Our results show that the characteristics of ocular drift are remarkably similar in the two species; a clear deviation from a scale-invariant spectrum occurs in the range between 50 and 100Hz, generally attributed to ocular tremor, leading to intersaccadic retinal speeds as high as 1.5deg/s. The amplitude of this deviation differs on the two axes of motion. In addition to our experimental observations, we suggest basic guidelines to evaluate the performance of eyetrackers and to optimize experimental conditions for the measurement of ocular drift and tremor.

Shear bond strength of brackets bonded with nanofilled flowable resins

To evaluate the shear bond strength of brackets fixed with different materials (two light-cured nanofilled low-viscosity resins – Transbond Supreme LV and Flow Tain LV and two light-cured traditional resins – Transbond XT and Transbond Plus Color Change) after 10 min and 24 h, and to evaluate the type of failure. Material and methods: Eighty bovine incisors were selected and randomly divided into groups (n = 10) according to the material and fixation period. The brackets were bonded following the manufacturer's instructions and stored in deionized water at 37oC for 10 min or 24 h. After, the specimens were submitted to shear bond strength test at 0.5 mm/min and evaluated for adhesive remnant index (ARI). The data were submitted to Kruskal Wallis and Wilcoxon tests (p &lt; 0.05) and the ARI scores to Chi-Square test. Results: There was a significant difference among the materials (p &lt; 0.05) (after 10 min – Transbond XT &gt; Transbond Plus Color Change &gt; Transbond Supreme LV = Flow Tain LV and after 24 h – Transbond XT &gt; Transbond Plus Color Change = Transbond Supreme LV =Flow Tain LV). There was no significant difference in resistance values between 10 min and 24 h, except for Transbond Plus Color Change. Most groups showed adhesive remaining adhered to the enamel (scores 2 and 3) without statistical significant difference (p &gt; 0.05). Conclusion: The light-cured traditional resins showed higher resistance than the nanofilled materials. The period of fixation had no influence on the resistance for different materials, except for Transbond Plus Color Change.

Immaturity of Visual Fixations in Dyslexic Children.

To our knowledge, behavioral studies recording visual fixations abilities in dyslexic children are scarce. The object of this article is to explore further the visual fixation ability in dyslexics compared to chronological age-matched and reading age-matched non-dyslexic children. Fifty-five dyslexic children from 7 to 14 years old, 55 chronological age-matched non-dyslexic children and 55 reading age-matched non-dyslexic children participated to this study. Eye movements from both eyes were recorded horizontally and vertically by a video-oculography system (EyeBrain® T2). The fixation task consisted in fixating a white-filled circle appearing in the center of the screen for 30 s. Results showed that dyslexic children produced a significantly higher number of unwanted saccades than both groups of non-dyslexic children. Moreover, the number of unwanted saccades significantly decreased with age in both groups of non-dyslexic children, but not in dyslexics. Furthermore, dyslexics made more saccades during the last 15 s of fixation period with respect to both groups of non-dyslexic children. Such poor visual fixation capability in dyslexic children could be due to impaired attention abilities, as well as to an immaturity of the cortical areas controlling the fixation system.

Photosystem-II shutdown evolved with Nitrogen fixation in the unicellular diazotroph Crocosphaera watsonii.

Protection of nitrogenase from oxygen in unicellular Cyanobacteria is obtained by temporal separation of photosynthesis and diazotrophy through transcriptional and translational regulations of nitrogenase. But diazotrophs can face environmental situations in which N2 fixation occurs significantly in the light, and we believe that another control operates to make it possible. The night-time shutdown of PSII activity is a peculiar behaviour that discriminates Crocosphaera watsonii WH8501 from any other phototroph, whether prokaryote or eukaryote. This phenomenon is not only due to the plastoquinone pool redox status, and suggests that the sentinel D1 protein, expressed in periods of nitrogen fixation, is inactive. Results demonstrate a tight constraint of oxygen evolution in C. watsonii as additional protection of nitrogenase activity and suggest a possible recycling of cellular components.

An Evaluation of the Effect of Therapeutic Ultrasound on Healing of Mandibular Fracture.

The mandible is the most frequently fractured bone in maxillofacial trauma, the treatment of which consists of reduction and fixation of dislocated fragments by open or closed approach. Innovative techniques toward reducing the period of the postoperative intermaxillary fixation (IMF) are being researched. A relatively unknown treatment that may have an effect on fracture healing is ultrasound. Recent clinical trials have shown that low-intensity pulsed ultrasound (LIPUS) has a positive effect on bone healing. The aim of this study was to evaluate the effect of LIPUS on healing by its application in fresh, minimally displaced or undisplaced mandibular fracture in young and healthy individuals. A total of 28 healthy patients were selected randomly from the outpatient department needing treatment of mandibular fractures. They were then randomly allocated to either of the following two groups-experimental group and study group. After IMF, patients in experimental group received pulsed ultrasound signals with frequency of 1 MHz, with temporal and spatial intensity of 1.5 W/cm(2), pulsed wave for 5 minutes on every alternate day for 24 days, whereas patients in control group received no therapy except IMF. Radiographic density at the fracture zone was assessed from the radiograph by Emago (Emago, Amsterdam, Netherlands) Image Analysis software before IMF then at 1st to 5th weeks post-IMF. The amount of clinical mobility between fracture fragments was assessed by digital manipulation of fractured fragment with the help of periodontal pocket depth measuring probe in millimeters at pre-IMF and after 3 weeks. Pain was objectively measured using a visual analogue scale at weekly interval. The data collected were subjected to unpaired "t" test. The experimental group showed significant improvement in radiographic density compared with control group at 3- and 5-week interval; pain perception was significantly reduced in experimental group compared with study group in the subsequent weeks. No significant difference was found in clinical mobility between fracture fragments at 3-week interval. The present study provides a basis for application of therapeutic controlled ultrasound as an effective treatment modality to accelerate healing of fresh, minimally displaced mandibular fracture.

Mandibular Ramus Fracture: An Overview of Rare Anatomical Subsite.

Aim. The present study aims at exemplifying the incidence, and aetiology and analyses the outcomes of open reduction internal fixation (ORIF) over closed treatment of mandibular ramus fractures. Patients and Method. In the present retrospective analysis of mandibular fracture patients, variables analysed were age, sex, cause of injury, pretreatment occlusion, treatment given, period of maxillo-mandibular fixation (MMF), and posttreatment occlusion. Results. Out of 388 mandibular fractures treated, ramus fractures were 12 (3.09%). In the present study, predominant cause of mandibular ramus fracture was road traffic accident (RTA) n = 07 (58.33%) followed by fall n = 04 (33.33%) and assault n = 1 (8.33%). The average age was 35.9 years with a male predilection. Of these, 9 patients were treated with ORIF while remaining 3 with closed treatment. The average MMF after closed treatment was 21 days and 3 to 5 days after ORIF. There was improvement in occlusion in all 12 patients posttreatment with no major complication except for reduced mouth opening in cases treated with ORIF which recovered with physiotherapy and muscle relaxants. Conclusion. Mandibular ramus fractures accounted for 3.09% with RTA as a common aetiology. ORIF of ramus fractures facilitated adequate functional and anatomic reduction with early return of function.

The Rise and Fall of an Evolutionary Innovation: Contrasting Strategies of Venom Evolution in Ancient and Young Animals.

Animal venoms are theorized to evolve under the significant influence of positive Darwinian selection in a chemical arms race scenario, where the evolution of venom resistance in prey and the invention of potent venom in the secreting animal exert reciprocal selection pressures. Venom research to date has mainly focused on evolutionarily younger lineages, such as snakes and cone snails, while mostly neglecting ancient clades (e.g., cnidarians, coleoids, spiders and centipedes). By examining genome, venom-gland transcriptome and sequences from the public repositories, we report the molecular evolutionary regimes of several centipede and spider toxin families, which surprisingly accumulated low-levels of sequence variations, despite their long evolutionary histories. Molecular evolutionary assessment of over 3500 nucleotide sequences from 85 toxin families spanning the breadth of the animal kingdom has unraveled a contrasting evolutionary strategy employed by ancient and evolutionarily young clades. We show that the venoms of ancient lineages remarkably evolve under the heavy constraints of negative selection, while toxin families in lineages that originated relatively recently rapidly diversify under the influence of positive selection. We propose that animal venoms mostly employ a ‘two-speed’ mode of evolution, where the major influence of diversifying selection accompanies the earlier stages of ecological specialization (e.g., diet and range expansion) in the evolutionary history of the species–the period of expansion, resulting in the rapid diversification of the venom arsenal, followed by longer periods of purifying selection that preserve the potent toxin pharmacopeia–the period of purification and fixation. However, species in the period of purification may re-enter the period of expansion upon experiencing a major shift in ecology or environment. Thus, we highlight for the first time the significant roles of purifying and episodic selections in shaping animal venoms.

Visual pop-out in barn owls: Human-like behavior in the avian brain.

Visual pop-out is a phenomenon by which the latency to detect a target in a scene is independent of the number of other elements, the distractors. Pop-out is an effective visual-search guidance that occurs typically when the target is distinct in one feature from the distractors, thus facilitating fast detection of predators or prey. However, apart from studies on primates, pop-out has been examined in few species and demonstrated thus far in rats, archer fish, and pigeons only. To fill this gap, here we study pop-out in barn owls. These birds are a unique model system for such exploration because their lack of eye movements dictates visual behavior dominated by head movements. Head saccades and interspersed fixation periods can therefore be tracked and analyzed with a head-mounted wireless microcamera--the OwlCam. Using this methodology we confronted two owls with scenes containing search arrays of one target among varying numbers (15-63) of similar looking distractors. We tested targets distinct either by orientation (Experiment 1) or luminance contrast (Experiment 2). Search time and the number of saccades until the target was fixated remained largely independent of the number of distractors in both experiments. This suggests that barn owls can exhibit pop-out during visual search, thus expanding the group of species and brain structures that can cope with this fundamental visual behavior. The utility of our automatic analysis method is further discussed for other species and scientific questions.

On the origin of a phosphate enriched interval in the Chattanooga Shale (Upper Devonian) of Tennessee—A combined sedimentologic, petrographic, and geochemical study

The Devonian Chattanooga Shale contains an uppermost black shale interval with dispersed phosphate nodules. This interval extends from Tennessee to correlative strata in Kentucky, Indiana, and Ohio and represents a significant period of marine phosphate fixation during the Late Devonian of North America. It overlies black shales that lack phosphate nodules but otherwise look very similar in outcrop. The purpose of this study is to examine what sets these two shales apart and what this difference tells us about the sedimentary history of the uppermost Chattanooga Shale.In thin section, the lower black shales (PBS) show pyrite enriched laminae and compositional banding. The overlying phosphatic black shales (PhBS) are characterized by phosbioclasts, have a general banded to homogenized texture with reworked layers, and show well defined horizons of phosphate nodules that are reworked and transported. In the PhBS, up to 8000 particles of P-debris per cm2 occur in reworked beds, whereas the background black shale shows between 37–88 particles per cm2. In the PBS, the shale matrix contains between 8–16 phosphatic particles per cm2. The shale matrix in the PhBS contains 5.6% inertinite, whereas just 1% inertinite occurs in the PBS. The shale matrix in both units is characterized by flat REE patterns (shale-normalized), whereas Phosbioclast-rich layers in the PhBS show high concentrations of REEs and enrichment of MREEs. Negative Ce-anomalies are common to all samples, but are best developed in association with Phosbioclasts. Redox-sensitive elements (Co, U, Mo) are more strongly enriched in the PBS when compared to the PhBS. Trace elements associated with organic matter (Cu, Zn, Cd, Ni) show an inverse trend of enrichment.Deposited atop a sequence boundary that separates the two shale units, the PhBS unit represents a transgressive systems tract and probably was deposited in shallower water than the underlying PBS interval. The higher phosphate content in the PhBS is interpreted as the result of a combination of lower sedimentation rates with reworking/winnowing episodes. Three types of phosphatic beds that reflect different degrees of reworking intensity are observed. Strong negative Ce anomalies and abundant secondary marcasite formation in the PhBS suggests improved aeration of the water column, and improved downward diffusion of oxygen into the sediment. The associated oxidation of previously formed pyrite resulted in a lowering of pore water pH and forced dissolution of biogenic phosphate. Phosphate dissolution was followed by formation of secondary marcasite and phosphate. Repeated, episodic reworking caused repetitive cycles of phosphatic dissolution and reprecipitation, enriching MREEs in reprecipitated apatite. A generally “deeper” seated redox boundary favored P-remineralization within the sediment matrix, and multiple repeats of this process in combination with wave and current reworking at the seabed led to the formation of larger phosphatic aggregates and concentration of phosphate nodules in discrete horizons.

The Demand and Supply of Mortgage Fixation Periods. Managing Interest Rate Risk and Credit Risk in a Low Rate Environment

We examine the determinants of households' and banks' choice of mortgage rate fixation periods (FP) in a low interest rate environment. The existing literature interprets equilibrium FP, often reduced to the choice between Fixed Rate Mortgages (FRM) and Adjustable Rate Mortgages (ARM), as purely demand driven. Using a unique dataset with offers from multiple banks for each mortgage request, we are the first to explicitly disentangle demand and supply determinants of FP choices. We show that banks can advance their own FP preferences along several dimensions. Their desired FP must account both for the implied Interest Rate Risk (IRR), and for the Credit Risk implications from shifting that IRR to households. Our empirical results confirm that banks do indeed take into account both types of risk, although some margins of response are used only to small extent.

Overlapping representations for reach depth and direction in caudal superior parietal lobule of macaques.

Reaching movements in the real world have typically a direction and a depth component. Despite numerous behavioral studies, there is no consensus on whether reach coordinates are processed in separate or common visuomotor channels. Furthermore, the neural substrates of reach depth in parietal cortex have been ignored in most neurophysiological studies. In the medial posterior parietal area V6A, we recently demonstrated the strong presence of depth signals and the extensive convergence of depth and direction information on single neurons during all phases of a fixate-to-reach task in 3-dimensional (3D) space. Using the same task, in the present work we examined the processing of direction and depth information in area PEc of the caudal superior parietal lobule (SPL) in three Macaca fascicularis monkeys. Across the task, depth and direction had a similar, high incidence of modulatory effect. The effect of direction was stronger than depth during the initial fixation period. As the task progressed toward arm movement execution, depth tuning became more prominent than directional tuning and the number of cells modulated by both depth and direction increased significantly. Neurons tuned by depth showed a small bias for far peripersonal space. Cells with directional modulations were more frequently tuned toward contralateral spatial locations, but ipsilateral space was also represented. These findings, combined with results from neighboring areas V6A and PE, support a rostral-to-caudal gradient of overlapping representations for reach depth and direction in SPL. These findings also support a progressive change from visuospatial (vergence angle) to somatomotor representations of 3D space in SPL.