bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics of active emmetropisation in young chicks – influence of sign and magnitude of imposed defocus
Authors: Hammond David S , Wallman Josh , Wildsoet Christine F
Published: May 2013

Purpose

Young eyes compensate for the defocus imposed by spectacle lenses by changing their rate of elongation and their choroidal thickness, bringing their refractive status back to the pre‐lens condition. We asked whether the initial rate of change either in the ocular components or in refraction is a function of the power of the lenses worn, a result that would be consistent with the existence of a proportional controller mechanism.

Methods

Two separate studies were conducted; both tracked changes in refractive errors and ocular dimensions. Study A: To study the effects of lens power and sign, young chicks were tracked for 4 days after they were fitted with positive (+5, +10 or +15 D) or negative (−5, −10, −15 D) lenses over one eye. In another experiment, biometric changes to plano, +1, +2 and +3 D lenses were tracked over a 24 h treatment period. Study B: Normal emmetropisation was tracked from hatching to 6 days of age and then a defocusing lens, either +6 D or −7 D, was fitted over one eye and additional biometric data collected after 48 h.

Results

In study A, animals treated with positive lenses (+5, +10 or +15 D) showed statistical similar initial choroid responses, with a mean thickening 24 μm h−1 over the first 5 h. Likewise, with the low power positive lenses, a statistically similar magnitude of choroidal thickening was observed across groups (+1 D: 46.0 ± 7.8 μm h−1; +2 D: 53.5 ± 9.9 μm h−1; +3 D 53.3 ± 24.1 μm h−1) in the first hour of lens wear compared to that of a plano control group. These similar rates of change in choroidal thickness indicate that the signalling response is binary in nature and not influenced by the magnitude of the myopic defocus. Treatments with −5, −10 and −15 D lenses induced statistically similar amounts of choroidal thinning, averaging −70 ± 15 μm after 5 h and −96 ± 45 μm after 24 h. Similar rates in inner axial length changes were also seen with these lens treatments until compensation was reached, once again indicating that the signalling response is not influenced by the magnitude of hyperopic defocus. In study B, after 48 h of +6 D lens treatment, the average refractive error and choroidal changes were found to be larger in magnitude than expected if perfect compensation had taken place, with a + 2.4 D overshoot in refractive compensation.

Conclusion

Taken together, our results with both weak and higher power positive lenses suggest that eye growth is guided more by the sign than by the magnitude of the defocus, and our results for higher power negative lenses support a similar conclusion. These behaviour patterns and the overshoot seen in Study B are more consistent with the behaviour of a bang‐bang controller than a proportional controller.
Minor oral surgery in a patient with a combined fracture and congenital malformation of the first cervical vertebra
Authors: O'Neill F. , Thayer T. , Balmer M.C. , Begley A.
Published: May 2013

Here we present a case study of a patient who presented with both a congenital failure of fusion of the posterior arch of the atlas and a concomitant Jefferson fracture of the anterior arch following trauma. This patient required minor oral surgery prior to open reduction and internal fixation of the fracture, and the considerations are discussed.
Predictors of Pacemaker Dependence and Pacemaker Dependence as a Predictor of Mortality in Patients with Implantable Cardioverter Defibrillator
Authors: SOOD NITESH , CRESPO ERIC , FRIEDMAN MEIR , GUERTIN DANETTE , ZWEIBEL STEVEN , KLUGER JEFFREY , CLYNE CHRISTOPHER A.
Published: May 2013

Background

The prevalence, predictors, and survival for the development of pacemaker dependence (PD) in patients implanted with an implantable cardioverter defibrillator (ICD) are unknown.

Methods

This was a retrospective analysis of 1,550 consecutive patients with ICD implantation at a single center from 1996 to 2008 with a mean of 4.2 ± 3.4 years. Patients with implant intrinsic heart rates less than 40 beats/min (n = 48) and cardiac resynchronization therapy (n = 444) were excluded leaving 1,058 patients in this study. PD was defined as an intrinsic rhythm <40 beats/min after inhibiting the pacemaker, <50 beats/min with transient symptoms of dizziness relieved by resumption of pacing and right ventricle pacing despite algorithms to promote intrinsic conduction at the 3 monthly follow‐up ICD clinic visits. Multivariate regression and Cox proportional hazard models were used for analysis.

Results

The mean age was 64 ± 13 years; 79% were male with a primary indication for the ICD in 57%. PD occurred in 142 (13.4%) of patients, with a mean time to PD of 2.6 ± 1.9 years. PD was associated with a 48% increased odds for mortality versus non‐PD ICD patients during the mean follow‐up time of 4.2 ± 3.4 years (adjusted odds ratio = 1.48 [95% confidence interval 1.080–2.042]; P = 0.015). Older age, a history of atrial fibrillation, amiodarone use, and secondary prevention were the strongest predictors for the development of PD.

Conclusions

In this single‐center ICD cohort, the development of PD was not uncommon and was associated with decreased survival.
Autonomic cardio‐respiratory reflex reactions and superselective ophthalmic arterial chemotherapy for retinoblastoma
Authors: Phillips Trudie J. , McGuirk Simon P. , Chahal Hardeep K. , Kingston Judith , Robertson Fergus , Brew Stefan , Roebuck Derek , Hungerford John L. , Herod Jane
Published: May 2013

Objective

To describe our experience with superselective ophthalmic artery chemotherapy (SOAC) in retinoblastoma and to report the serious adverse cardio‐respiratory reactions we have observed.

Methods

SOAC was performed using a standardized protocol for general anesthesia, ophthalmic artery catheterization, and pulsed infusion of melphalan. Adverse reactions were defined as those in which the patient required active treatment to maintain cardio‐respiratory stability.

Results

Between December 2008 and May 2012, 54 eyes in 52 patients were treated. 143 catheterization procedures were performed, with a technical success rate of 93% (n = 133). There were no deaths or major complications. Adverse cardio‐respiratory reactions developed during 35 procedures (24%; 95% CI, 18–32%). All reactions occurred during second or subsequent catheterization procedures (39%; 95% CI, .29–49%) and were characterized by hypoxia, reduced lung compliance, systemic hypotension and bradycardia. Adverse events were successfully treated in all patients. One procedure was abandoned due to prolonged hemodynamic instability.

Conclusion

Adverse cardio‐respiratory reactions are commonly observed in SOAC for retinoblastoma. We believe that the adverse clinical signs represent an autonomic reflex response, akin to the trigemino‐cardiac or oculo‐respiratory reflexes, and all patients should be considered at‐risk. Reactions occur only during second or subsequent procedures and can be life‐threatening. The routine use of intravenous atropine does not seem to have altered the incidence or severity of these reactions. Anesthetists and interventional neuroradiologists involved in SOAC must be vigilant to ensure adverse reactions, when they develop, are treated quickly and effectively.
Postoperative pain, nausea and vomiting following adeno‐tonsillectomy – a long‐term follow‐up
Authors: Stanko Dana , Bergesio Ric , Davies Kylie , Hegarty Mary , von Ungern‐Sternberg Britta S.
Published: May 2013

Background

Adenotonsillectomy is a common pediatric surgical procedure. Our knowledge of the recovery profile, parental understanding, and expectations is limited. We aimed to assess the incidence of pain, nausea, and vomiting in children undergoing adenotonsillectomy on postoperative day 3 and 7. We also wished to evaluate parental understanding regarding discharge instructions as well as parental expectations and experience of their child's recovery.

Methods

We enrolled 100 children (0–16 years) undergoing elective adenotonsillectomy. On day 3 and 7, parents were questioned about their child's level of pain, nausea/vomiting and their understanding regarding postoperative instructions.

Results

Hundred children (median, 6.68 years) were recruited. 52% of parents rated their child's pain as VAS ≥ 5 on day 3, dropping to 30% by day 7. Almost 33% of patients experienced nausea on day 3, dropping to 11.6% by day 7. A similar trend was observed for postoperative vomiting. Most parents, 89%, agreed that postoperative instructions were clear. However, knowledge regarding when to seek emergency medical advice was found to be lacking. On day 7, only 44% of parents reported that their child's recovery met their expectations.

Conclusion

Adenotonsillectomy is associated with significant pain and PONV, persisting into the seventh postoperative day. Parental education and information seems inadequate and needs to be improved.
Use of the Bonfils intubating fibrescope in a baby with a severely compromised airway
Authors: Krishnan Priya L. , Thiessen Bernd H.
Published: May 2013

We report the successful use of a 2‐mm rigid Bonfils intubation endoscope as a rescue device in a 5‐week‐old baby presenting with an unstable airway due to massive macroglossia and multiple hemorrhagic lymphangiomata compressing the airway and resulting in a Cormack and Lehane grade 4 view. The limited intraoral space rendered it impossible to visualize the laryngeal inlet or insert a laryngeal mask, Glidescope or Airtraq blade into the patient's mouth. A 2‐mm Bonfils fibrescope passed easily into the patient's mouth and facilitated a grade 1 view of the laryngeal inlet with subsequent successful intubation at first attempt with a 3.5‐mm uncuffed endotracheal tube. There are very few alternatives to rescue such an airway in this age group with this type of pathology and surgical intervention would have been difficult due to the vascular nature of the lesion. Bonfils intubation endoscopes (Karl Storz Endoscopy, Tuttlingen, Germany) are a series of reusable devices consisting of a rigid metal tube with a fixed 40° anterior tip curvature containing a fibreoptic bundle. They are available in three sizes with outside diameters of 2, 3.5, or 5 mm. The advantage of the pediatric 2‐mm Bonfils fibrescope is that it allows intubation with a 2.5‐mm endotracheal tube. There is a paucity of the literature pertaining to the use of the Bonfils endoscope as a rescue device for intubation of small infants and neonates. In our case, the infant's airway was compromised as a result of a receding mandible, large protruding tongue, glottic distortion, and limited intraoral space. This prevented the use of bulkier rescue airway devices with the potential for traumatic manipulation, which could have lead to rapid deterioration of an already unstable airway. We feel that many clinicians are unaware of the benefits of the Bonfils fibrescope and suggest further studies to increase its use in elective and emergency situations.
Robust closed‐loop control of induction and maintenance of propofol anesthesia in children
Authors: West Nicholas , Dumont Guy A. , van Heusden Klaske , Petersen Christian L. , Khosravi Sara , Soltesz Kristian , Umedaly Aryannah , Reimer Eleanor , Ansermino J. Mark
Published: May 2013

Background

During closed‐loop control, a drug infusion is continually adjusted according to a measure of clinical effect (e.g., an electroencephalographic depth of hypnosis (DoH) index). Inconsistency in population‐derived pediatric pharmacokinetic/pharmacodynamic models and the large interpatient variability observed in children suggest a role for closed‐loop control in optimizing the administration of intravenous anesthesia.

Objective

To clinically evaluate a robustly tuned system for closed‐loop control of the induction and maintenance of propofol anesthesia in children undergoing gastrointestinal endoscopy.

Methods

One hundred and eight children, aged 6–17, ASA I‐II, were enrolled. Prior to induction of anesthesia, NeuroSENSE™ sensors were applied to obtain the WAVCNS DoH index. An intravenous cannula was inserted and lidocaine (0.5 mg·kg−1) administered. Remifentanil was administered as a bolus (0.5 μg·kg−1), followed by continuous infusion (0.03 μg·kg−1·min−1). The propofol infusion was closed‐loop controlled throughout induction and maintenance of anesthesia, using WAVCNS as feedback.

Results

Anesthesia was closed‐loop controlled in 102 cases. The system achieved and maintained an adequate DoH without manual adjustment in 87/102 (85%) cases. Induction of anesthesia (to WAVCNS ≤ 60) was completed in median 3.8 min (interquartile range (IQR) 3.1–5.0), culminating in a propofol effect‐site concentration (Ce) of median 3.5 μg·ml−1 (IQR 2.7–4.5). During maintenance of anesthesia, WAVCNS was measured within 10 units of the target for median 89% (IQR 79–96) of the time. Spontaneous breathing required no manual intervention in 91/102 (89%) cases.

Conclusions

A robust closed‐loop system can provide effective propofol administration during induction and maintenance of anesthesia in children. Wide variation in the calculated Ce highlights the limitation of open‐loop regimes based on pharmacokinetic/pharmacodynamic models.
The perioperative course of factor XIII and associated chest tube drainage in newborn and infants undergoing cardiac surgery
Authors: Gertler Ralph , Martin Klaus , Hapfelmeier Alexander , Tassani‐Prell Peter , Braun Siegmund , Wiesner Gunther
Published: May 2013

Background

Perioperative acquired factor XIII deficiency has been looked upon as a potential cause of postoperative bleeding in adult cardiac surgery.

Methods

Forty‐four infants were prospectively studied for the time course of factor XIII in plasma and the effect on chest tube drainage (CTD) and transfusion requirements in the first 24 h after surgery. A reconstituted blood prime (RBP) with fresh–frozen plasma (FFP) and packed red blood cells (PRBC) was used. Samples were taken at baseline, after cardiopulmonary bypass and upon arrival in the ICU. Differences in blood loss and transfusion requirements based on a cutoff value of 70% factor XIII activity at the time of ICU admission were also calculated.

Results

Baseline factor XIII activity was 79%, decreased to 71% after CPB (P = 0.102) and increased back up to 77% at ICU arrival (P = 0.708). There was no significant correlation between factor XIII, CTD, age, cyanosis, platelet count, and transfusion requirements at any time point. Only preoperative fibrinogen levels correlated significantly with factor XIII activity. Perioperative blood transfusions (PRBC P = 0.712, FFP P = 0.909, platelets P = 0.807) and chest tube losses (P = 0.424 at 6 h and P = 0.215 at 24 h) were not significantly different above or below a 70% factor XIII activity at ICU arrival.

Conclusion

Factor XIII activity in infants with congenital heart defects is within the lower range of normal adults, independent of patient's age and the presence of cyanosis. Reconstituted blood prime maintains factor XIII activity at sufficient levels during pediatric cardiac surgery. We could not detect a correlation between FXIII and CTD.
Capillary Malformation—Arteriovenous Malformation Syndrome: Review of the Literature, Proposed Diagnostic Criteria, and Recommendations for Management
Authors: Orme Charisse M. , Boyden Lynn M. , Choate Keith A. , Antaya Richard J. , King Brett A.
Published: May 2013

Capillary malformation–arteriovenous malformation syndrome is an autosomal dominant disorder caused by mutations in the RASA1 gene and characterized by multiple small, round to oval capillary malformations with or without arteriovenous malformations. Ateriovenous malformations occur in up to one‐third of patients and may involve the brain and spine. Although making the diagnosis is straightforward in some patients, there are other patients for whom diagnostic criteria may be helpful in their evaluation. Here we review the literature regarding capillary malformation−arteriovenous malformation syndrome, propose diagnostic criteria, and discuss the care of patients with this condition.
Transporter Associated with Antigen Processing Deficiency Syndrome: Case Report of an Adolescent with Chronic Perforated Granulomatous Skin Lesions Due to TAP2 Mutation
Authors: Konstantinou Paschalis , Kanariou Maria , Giliani Silvia C. , Pantelidaki Aikaterini , Kokolakis Athanasios , Tosca Androniki
Published: May 2013

A previously unreported case of transporter associated with antigen processing (TAP) deficiency syndrome (with no parental consanguinity) due to a homozygous TAP2 mutation is presented. Characteristic nonhealing, chronic, ulcerative granulomatous leg lesions combined with recurrent otitis media and sinopulmonary infections led to this boy being diagnosed at 15 years old. The role of the dermatologist was crucial in making the correct diagnosis and thereby positively influencing the quality of life and life expectancy of this boy.
The interactions and essential effects of intrinsic insulin‐like growth factor‐I on Leishmania (Leishmania) major growth within macrophages
Authors: Reis L. C. , Ramos‐Sanchez E. M. , Goto H.
Published: May 2013

Previously, we showed in Leishmania infections that extrinsic insulin‐like growth factor (IGF)‐I favored Leishmania proliferation and leishmaniasis development. In this study, the interaction of intrinsically expressed IGF‐I and Leishmania (Leishmania) major in macrophages was addressed, and a key finding was the observation, using confocal microscopy, of the co‐localization of IGF‐I and parasites within macrophages. Following stimulation with interferon‐γ (IFN‐γ), which is known to inhibit IGF‐I production in macrophages, we observed a reduction in the expression of both IGF‐I mRNA and protein. This reduced expression was accompanied by a reduction in the cellular parasite load that was completely recovered with the addition of extrinsic IGF‐I, which suggests an essential role for IGF‐I in Leishmania growth.
Comparative molecular analysis ofBursaphelenchus vallesianus, a wood‐inhabiting nematode isolated from declining pine trees in theCzechRepublic
Authors: Marek M. , Zouhar M. , Douda O. , Gaar V. , Ryšánek P.
Published: May 2013

TheBursaphelenchusgenus (Nematoda:Parasitaphelenchidae) comprises mostly wood‐inhabiting nematodes that feed on various tree‐colonizing fungi. One species of the genus,B. xylophilus, has been proven as an agent causing pine wilt disease (PWD). However, involvement of otherBursaphelenchusspecies in thePWDremains enigmatic. In the current paper, comparative molecular analysis is performed based on nuclear ribosomalDNA(rDNA) ofB. vallesianus, a species that was recently isolated from pine trees (Pinus sylvestris) exhibiting wilting and declining symptoms in theCzechRepublic. Sequencing of the nuclear‐encodedITS1–5·8S–ITS2 rDNAregion confirmed previous taxonomic conclusions based on morphology. Evolutionary reconstructions resulted in a phylogenetic tree, where theCzech isolate ofB. vallesianusoccupied a common clade together with other species belonging to the so‐calledB. sexdentatigroup. Unexpectedly, comprehensive analysis of the sequence data revealed a genetic variation distinguishing theCzech isolate ofB. vallesianusfrom all other species of theB. sexdentatigroup. This dissimilarity consists of the presence of a four nucleotide exchange found in the 5·8S rRNA‐coding gene. The newly identified genetic variation appears to affect the 5·8S rRNAfolding, as deduced from secondary structure models. Additionally, it is shown that for the first time, to the authors’ knowledge, both bursaphelenchid internal transcribed spacers (ITS1 andITS2) fold into the multibranched closed loops. While theITS2 closed loop is formed with help of canonical 5·8S‐28SrRNApairing, theITS1 forms the thermodynamically stable closed loop with no support of flanking rRNAsequences. The current information on bursaphelenchidITSrDNAsequence diversity and structure is further discussed.
Current status of cucurbit viruses in Venezuela and characterization of Venezuelan isolates of Zucchini yellow mosaic virus
Authors: Romay G. , Lecoq H. , Geraud‐Pouey F. , Chirinos D. T. , Desbiez C.
Published: May 2013

In Venezuela, cucurbit viruses have been associated with important yield losses. Therefore, an extensive survey was conducted to determine the major cucurbit viruses in this country. Leaf samples from 284 cucurbit plants exhibiting virus‐like symptoms were collected mainly in 2009–2010 from several states of Venezuela. They were assessed for viral infection by polymerase chain reaction (PCR) for Melon chlorotic mosaic virus (MeCMV) and reverse transcriptase (RT)‐PCR for Papaya ringspot virus (PRSV), Zucchini yellow mosaic virus (ZYMV), Watermelon mosaic virus (WMV), Cucumber mosaic virus (CMV), Squash mosaic virus (SqMV) and Cucurbit aphid‐borne yellows virus (CABYV). The most common virus in cucurbit fields, MeCMV, was present in 65·8% of samples. Its associated alphasatellite was found in 78% of samples positive for MeCMV. PRSV, ZYMV and WMV were found with different prevalence: 34·2, 32·4 and 1·1% respectively. CMV was also detected (6·7%) but SqMV and CABYV were not found. Single infections were more frequent than mixed infections (56·4 and 38·6%, respectively). For ZYMV, comparison and phylogenetic analyses of either polymerase and coat protein (NIb‐CP) partial sequences or CP complete sequences revealed a low genetic diversity within Venezuelan isolates. Thirty‐four ZYMV isolates were used for serological and biological analysis. Thirteen monoclonal antibodies showed a major group of isolates spread in several states and two groups located in Zulia only. Venezuelan ZYMV isolates showed biological variability on cucurbit cultivars susceptible, tolerant or resistant to ZYMV. Resistance to ZYMV in cucumber appears potentially durable, whereas resistance or tolerance in zucchini and melon may be easily overcome.
Validation of SAPS3 admission score and its customization for use in Korean intensive care unit patients: A prospective multicentre study
Authors: Lim So Yeon , Koh Shin Ok , Jeon Kyeongman , Na Sungwon , Lim Chae‐Man , Choi Won‐Il , Lee Young‐Joo , Kim Seok Chan , Chon Gyu Rak , Kim Je Hyeong , Kim Jae Yeol , Lim Jaemin , Rhee Chin Kook , Park Sunghoon , Kim Ho Cheol , Lee Jin Hwa , Lee Ji Hyun , Park Jisook , Koh Younsuck , Suh Gee Young ,   The Validation of Simplified acute physiology score 3 in Korean Intensive care unit (VSKI) study group,   Korean Study group on Respiratory Failure (KOSREF)
Published: May 2013

Background and objective

To externally validate the simplified acute physiology score 3 (SAPS3) and to customize it for use in Korean intensive care unit (ICU) patients.

Methods

This is a prospective multicentre cohort study involving 22 ICUs from 15 centres throughout Korea. The study population comprised patients who were consecutively admitted to participating ICUs from 1 July 2010 to 31 January 2011.

Results

A total of 4617 patients were enrolled. ICU mortality was 14.3%, and hospital mortality was 20.6%. The patients were randomly assigned into one of two cohorts: a development (n = 2309) or validation (n = 2308) cohort. In the development cohort, the general SAPS3 had good discrimination (area under the receiver operating characteristics curve = 0.829), but poor calibration (Hosmer–Lemeshow goodness‐of‐fit test H = 123.06, P < 0.001, C = 118.45, P < 0.001). The Australasia SAPS3 did not improve calibration (H = 73.53, P < 0.001, C = 70.52, P < 0.001). Customization was achieved by altering the logit of the original SAPS3 equation. The new equation for Korean ICU patients was validated in the validation cohort, and demonstrated both good discrimination (area under the receiver operating characteristics curve = 0.835) and good calibration (H = 4.61, P = 0.799, C = 5.67, P = 0.684).

Conclusions

General and regional Australasia SAPS3 admission scores showed poor calibration for use in Korean ICU patients, but the prognostic power of the SAPS3 was significantly improved by customization. Prediction models should be customized before being used to predict mortality in different regions of the world.
Psychophysiological and stress responses to competition in team sport coaches: An exploratory study
Authors: Hudson J. , Davison G. , Robinson P.
Published: May 2013

Examinations of stress in coaches have mainly been qualitative and focused on chronic stressors. This exploratory study examined stress responses in coaches during competition, including psychological and physiological indices. Using reversal theory, we examined metamotivational state profiles during competition. Ten male team sport coaches (mean age 39.8 ± 13.12 years) reported levels of subjective stress, pleasant and unpleasant emotions, metamotivational state, and provided saliva samples, on a competition day: 15 min prior to the pre‐match team talk; start of the match; end of the first half; start of the second half, and end of the match, then at equivalent times on a noncompetition day. Saliva samples were assayed for alpha‐amylase activity. On competition day, alpha‐amylase activity was significantly higher, as were subjective stress, arousal, and unpleasant emotions. Prior to and during active play, participants were mainly in the conformist, alloic (other‐oriented), and mastery states, and at the end of the match, in the telic and sympathy states. Only 22 metamotivational state reversals were observed, mostly at the start and end of the match. The elevated levels of subjective stress, alpha‐amylase activity, and unpleasant emotions suggest that educational programs may be useful for some coaches to manage psychological states during competition.
“The margin for error”: Ritual coping with cultural pressures
Authors: Broch T. B. , Kristiansen E.
Published: May 2013

Meritocratic sport cultures, media attention, coaches' ambitions, and “enthused” parents create stress and make coping pivotal for athletes' performance. A transdisciplinary dialogue between a sports‐sociologist and a sport‐psychologist manifests ritual practices in athletes' lived sport experiences as coping strategies. Based on two empirical strands, field observations of boy's handball and interviews with elite male wrestlers', analysis of pregame routines scrutinize psychosocial dimensions of athletes' ritual practice. The implications of ritual meaning making are investigated as a means to cope with sport specific sociocultural anxieties. Rituals are interpreted as psychosocial processes applied to construct perceived order and comfort in stressful sport milieus. We contend that it is reasonable to believe that successful coping is not solely because of athletes' psychological competencies and experiences, but also their ability to ritually use culture in meaningful ways. To manifest important contextual aspects of athletes' lived sport experiences, to nurture task‐oriented sport milieus, and to create change in sport and physical cultural contexts, we consequently suggest that the cultural meanings applied in ritual should be an important aspect to address.
Multiple tubulins: evolutionary aspects and biological implications
Authors: Breviario Diego , Gianì Silvia , Morello Laura
Published: May 2013

Plant tubulin is a dimeric protein that contributes to formation of microtubules, major intracellular structures that are involved in the control of fundamental processes such as cell division, polarity of growth, cell‐wall deposition, intracellular trafficking and communications. Because it is a structural protein whose function is confined to the role of microtubule formation, tubulin may be perceived as an uninteresting gene product, but such a perception is incorrect. In fact, tubulin represents a key molecule for studying fundamental biological issues such as (i) microtubule evolution (also with reference to prokaryotic precursors and the formation of cytomotive filaments), (ii) protein structure with reference to the various biochemical features of members of theFstZ/tubulin superfamily, (iii) isoform variations contributed by the existence of multi‐gene families and various kinds of post‐translational modifications, (iv) anti‐mitotic drug interactions and mode of action, (v) plant and cell symmetry, as determined using a series of tubulin mutants, (vi) multiple and sophisticated mechanisms of gene regulation, and (vii) intron molecular evolution. In this review, we present and discuss many of these issues, and offer an updated interpretation of the multi‐tubulin hypothesis.
Cotton GhCKI disrupts normal male reproduction by delaying tapetum programmed cell death via inactivating starch synthase
Authors: Min Ling , Zhu Longfu , Tu Lili , Deng Fenglin , Yuan Daojun , Zhang Xianlong
Published: May 2013

Anther infertility under high temperature (HT) conditions is a critical factor contributing to yield loss in cotton (Gossypium hirsutum). Using large‐scale expression profile sequencing, we studied the effect of HT on cotton anther development. Our analysis revealed that altered carbohydrate metabolism or disrupted tapetal programmed cell death (PCD) underlie anther sterility. Expression of the Gossypium hirsutum casein kinase I (GhCKI) gene, which encodes a homolog of casein kinase I (CKI), was induced in an HT‐sensitive cotton line after exposure to HT. As mammalian homologs of GhCKI are involved in inactivation of glycogen synthase and the regulation of apoptosis, GhCKI may be considered a target gene for improving anther fertility under HT conditions. Our studies suggest that GhCKI exhibits starch synthase kinase activity, increases glucose content in early‐stage buds and activates the accumulation of abscisic acid, thereby disturbing the balance of reactive oxygen species and eventually disrupting tapetal PCD, leading to anther abortion or indehiscence. These results indicate that GhCKI may be a key regulator of tapetal PCD and anther dehiscence, with the potential to facilitate regulation of HT tolerance in crops.
ULTRASONOGRAPHIC CHARACTERISTICS OF THE CISTERNA CHYLI IN EIGHT DOGS AND FOUR CATS
Authors: Etienne Anne‐Laure , Cavrenne Romain , Gommeren Kris , Bolen Géraldine , Busoni Valeria
Published: May 2013

Ultrasonography of the cisterna chyli has been used in humans to diagnose increased lymphatic flow or lymph flow obstruction and to guide percutaneous embolization of the thoracic duct via the cisterna chyli. The aim of this study was to describe the ultrasonographic characteristics of the dorsal portion of cisterna chyli in dogs and cats with chylous ascites or chylothorax and in a group of healthy dogs and cats. The aorta and the cranial mesenteric artery were used as anatomic landmarks. Ultrasonography was performed before and 2 h after a fatty meal in healthy dogs and cats. The visualized structure was confirmed to be a dilated cisterna chyli at necropsy in a dog with chylous ascites. The confirmed or presumed cisterna chyli was consistently detected using ultrasonography in nonfasted healthy animals and clinically affected animals and appeared as an anechoic tubular structure, without detectable flow, at the right dorsolateral aspect of the aorta. It had a similar ultrasonographic appearance in patients with chyloabdomen and in nonfasted healthy dogs and cats. There was considerable overlap in diameters of the cisterna chyli for affected and healthy animals. The shape and size of the cisterna chyli in an individual animal were variable during the same ultrasound examination and between different examinations. This study demonstrated the appearance of the presumed dorsal portion of the cisterna chyli by ultrasonography and might provide useful preliminary data for further studies into the feasibility of ultrasound‐guided injections or aspirations of the cisterna chyli in dogs and cats.
PREVALENCE, ASSOCIATION WITH STIFLE CONDITIONS, AND HISTOPATHOLOGIC CHARACTERISTICS OF TIBIAL TUBEROSITY RADIOLUCENCIES IN DOGS
Authors: Paek Matthew , Engiles Julie B. , Mai Wilfried
Published: May 2013

A tibial tuberosity radiolucency is sometimes identified on lateral radiographs of canine stifle joints, however little is known about the cause or significance. The purpose of this study was to describe the prevalence, association with other stifle conditions, and histopathologic characteristics of tibial tuberosity radiolucencies in a group of dogs. Radiographs of all canine stifle joints over 5 years were evaluated. Presence or absence of a tibial tuberosity radiolucency was recorded by an observer who was unaware of clinical status. Patient signalment and presence of other stifle joint conditions were recorded from medical records. A tibial tuberosity radiolucency was found in 145/675 dogs (prevalence = 21.5%). Statistically significant associations were identified between tibial tuberosity radiolucency and stifle condition (P< 0.0001), breed size (P= 0.011), and younger age of presentation (P= 0.001), but not with gender (P= 0.513). Dogs with a tibial tuberosity radiolucency had higher odds of having a medial patellar luxation than dogs without (OR= 9.854,P< 0.0001, 95%CI6.422–15.120). Dogs with a tibial tuberosity radiolucency had lower odds of having a cranial cruciate ligament rupture than dogs without (OR= 0.418,P< 0.0001, 95%CI0.287–0.609). Four canine cadavers, two with normal stifles and two with tibial tuberosity radiolucencies, underwent radiographic, computed tomographic, and histologic examination of the stifles. Computed tomography revealed a hypoattenuating cortical defect in the lateral aspect of the proximal tibial tuberosity that corresponded histopathologically to a hyaline cartilage core. Findings indicated that the tibial tuberosity radiolucency may be due to a retained cartilage core and associated with medial patellar luxation in dogs.
Trafficking of molecules between parasitic plants and their hosts
Authors: Aly R
Published: May 2013

Parasitic plants have evolved various methods of invading host plants. Some invade aerial parts, whereas others invade the roots to obtain necessary nutrients for their development. Phelipanche and Orobanche spp. (broomrapes) and Cuscuta spp. (dodders) are holoparasitic plants that subsist on roots and shoots, respectively, of a variety of agricultural crops. These weeds are able to connect directly with the vascular system of the host, thereby acquiring the water, minerals and carbohydrates necessary for their own growth and reproduction. This exploitation by parasitic plants often causes severe losses in yield quality and quantity of host crops. The key to an effective means for controlling parasitic plants lies in the development of resistant crops, supported by an improved understanding of broomrape and dodder biology. The haustoria formed at the junctions of parasite and host open the way for translocation of a variety of molecules and macromolecules from the host to the parasite. At the same time, however, the haustoria also open opportunities for the development of methods to control parasitic plants. This review will summarise the current knowledge on translocation of siRNAs, mRNAs, viruses, sugars, proteins and herbicides from host to parasitic plants and the potential significance of such molecules to the parasite. Improved understanding of the molecular exchange between host plants and their parasites is expected to lead to the development of state‐of‐the‐art, effective approaches to parasitic weed management.
Progressive cone beam CT dose control in image‐guided radiation therapy
Authors: Yan Hao , Zhen Xin , Cerviño Laura , Jiang Steve B. , Jia Xun
Published: May 2013

Purpose:

Cone beam CT (CBCT) in image‐guided radiotherapy (IGRT) offers a tremendous advantage for treatment guidance. The associated imaging dose is a clinical concern. One unique feature of CBCT‐based IGRT is that the same patient is repeatedly scanned during a treatment course, and the contents of CBCT images at different fractions are similar. The authors propose a progressive dose control (PDC) scheme to utilize this temporal correlation for imaging dose reduction.

Methods:

A dynamic CBCT scan protocol, as opposed to the static one in the current clinical practice, is proposed to gradually reduce the imaging dose in each treatment fraction. The CBCT image from each fraction is processed by a prior‐image based nonlocal means (PINLM) module to enhance its quality. The increasing amount of prior information from previous CBCT images prevents degradation of image quality due to the reduced imaging dose. Two proof‐of‐principle experiments have been conducted using measured phantom data and Monte Carlo simulated patient data with deformation.

Results:

In the measured phantom case, utilizing a prior image acquired at 0.4 mAs, PINLM is able to improve the image quality of a CBCT acquired at 0.2 mAs by reducing the noise level from 34.95 to 12.45 HU. In the synthetic patient case, acceptable image quality is maintained at four consecutive fractions with gradually decreasing exposure levels of 0.4, 0.1, 0.07, and 0.05 mAs. When compared with the standard low‐dose protocol of 0.4 mAs for each fraction, an overall imaging dose reduction of more than 60% is achieved.

Conclusions:

PINLM‐PDC is able to reduce CBCT imaging dose in IGRT utilizing the temporal correlations among the sequence of CBCT images while maintaining the quality.
The effect of element strength assignment on the torsional response of stiffness-eccentric systems
Authors: Georgoussis George K.
Published: May 2013

Building structures of low or medium height are usually designed with a pseudostatic approach using a base shear much lower than that predicted from an elastic spectrum. Given this shear force, the objective of this paper is to evaluate the effect of the element strength assignment (as determined by several building codes) on the torsional response of inelastic single-storey eccentric structures and to provide guidelines for minimizing this structural behaviour. It is demonstrated that the expected torque about the centre of mass (CM) may be, with equal probability, positive (counterclockwise) or negative (clockwise). This result means that the torsional strength should also be provided in equal terms in both rotational directions, and therefore the base shear and torque (BST) surface of a given system must be symmetrical (or approximately symmetrical). In stiffness-eccentric systems, appropriate BST surfaces may be obtained when a structural design is based on a pair of design eccentricities in a symmetrical order about CM, and this is shown in representative single-storey building models under characteristic ground motions.
Isolation of Burkholderia cepacia JB12 from lead- and cadmium-contaminated soil and its potential in promoting phytoremediation with tall fescue and red clover
Authors: Jin Zhong Min , Sha Wei , Zhang Yan Fu , Zhao Jing , Ji Hongyang
Published: May 2013

Phytoremediation combined with suitable microorganisms and biodegradable chelating agents can be a means of reclaiming lands contaminated by toxic heavy metals. We investigated the ability of a lead- and cadmium-resistant bacterial strain (JB12) and the biodegradable chelator ethylenediamine-N,N′-disuccinic acid (EDDS) to improve absorption of these metals from soil by tall fescue and red clover. Strain JB12 was isolated from contaminated soil samples, analysed for lead and cadmium resistance, and identified as Burkholderia cepacia. Tall fescue and red clover were grown in pots to which we added JB12, (S,S)-EDDS, combined JB12 and EDDS, or water only. Compared with untreated plants, the biomass of plants treated with JB12 was significantly increased. Concentrations of lead and cadmium in JB12-treated plants increased significantly, with few exceptions. Plants treated with EDDS responded variably, but in those treated with combined EDDS and JB12, heavy metal concentrations increased significantly in tall fescue and in the aboveground parts of red clover. We conclude that JB12 is resistant to lead and cadmium. Its application to the soil improved the net uptake of these heavy metals by experimental plants. The potential for viable phytoremediation of lead- and cadmium-polluted soils with tall fescue and red clover combined with JB12 was further enhanced by the addition of EDDS.
Importance of body size and hunting strategy during interactions between the Mexican red-rump tarantula (Brachypelmavagans) and the wolf spiderLycosasubfusca
Authors: Dor A. , Hénaut Y.
Published: May 2013

Behavioural adaptation helps animals to maximize their ability to obtain food and to avoid being eaten, increasing fitness. To achieve this, they must assess predation risk and evaluate foraging needs simultaneously. In two sympatric spider species, the wandering wolf spider Lycosa subfusca F.O.P. Cambridge, 1902 and the sit-and-wait Mexican red-rump tarantula (Brachypelma vagans Ausserer, 1875), we studied the relationship between predatory behaviour and antipredatory behaviour at different life stages. In the laboratory, encounters were organized between one wolf spider (small, medium-sized, or large) and one tarantula (spiderling, small, medium-sized, or large). Attack latencies and behaviours were recorded. The results showed that wolf spiders attacked and successfully captured younger tarantulas, while they avoided or retreated from older ones. Tarantulas preferentially attacked and captured older wolf spiders. On other hand, younger wolf spiders were more cautious than older ones, which waited until for the tarantulas to attack before retreating. Younger tarantulas were also more cautious than adults, which never retreated from attack and increased their success in attacks with age. Finally, we discuss the relationship between the predatory strategies of both spiders with their perception abilities and life history.
Functional morphology of the female genital organs in the wild ring-tailed coati (Nasua nasua) in the northeastern Peruvian Amazon
Authors: Mayor P. , Montes D. , López-Plana C.
Published: May 2013

This study examines the functional morphology of genital organs of 45 wild female ring-tailed coatis (Nasua nasua (L., 1766)) in the Peruvian Amazon. The coati shows a seasonal reproductive pattern, with a concentration of births between January and March. The pregnancy rate during the reproductive season was 64.7%. Mean litter size was 4.2 fetuses and mean ovulation rate was 4.5 follicles per pregnant female, resulting in a low rate of embryo or oocyte mortality of 9.8%. The observed vaginal pattern in our study suggests that vaginal cytology could be a useful indicator for the phase of estrus. The present evaluation provides reproductive information that may be a key component in the development of management strategies for both captive and wild coati populations.
THE STORY OF QUARKS
Authors: GELL-MANN MURRAY
Published: May 2013

This public lecture was presented at the National University of Singapore on the 5th of March, 2013. It was organized by the Institute of Advanced Studies as part of the Distinguished Public Lecture series.
THE THEORY OF PSEUDOKNOTS
Authors: HENRICH ALLISON , HOBERG REBECCA , JABLAN SLAVIK , JOHNSON LEE , MINTEN ELIZABETH , RADOVIĆ LJILJANA
Published: May 2013

Classical knots in ℝ3 can be represented by diagrams in the plane. These diagrams are formed by curves with a finite number of transverse crossings, where each crossing is decorated to indicate which strand of the knot passes over at that point. A pseudodiagram is a knot diagram that may be missing crossing information at some of its crossings. At these crossings, it is undetermined which strand passes over. Pseudodiagrams were first introduced by Ryo Hanaki in 2010. Here, we introduce the notion of a pseudoknot, i.e. an equivalence class of pseudodiagrams under an appropriate choice of Reidemeister moves. In order to begin a classification of pseudoknots, we introduce the concept of a weighted resolution set, or WeRe-set, an invariant of pseudoknots. We compute the WeRe-set for several pseudoknot families and discuss extensions of crossing number, homotopy, and chirality for pseudoknots.
SELECTIVE EXCITATION OF COHERENT ANTI-STOKES RAMAN SCATTERING VIA PHASE STEP MODULATION
Authors: XU SHUWU , HUANG YUNXIA , JI XIANMING
Published: May 2013

It is known that femtosecond coherent anti-Stokes Raman scattering (CARS) method suffers from the drawback of poor selectivity between neighboring Raman energy levels due to the large bandwidth of the pulses. Quantum coherent control based on the ultrashort pulse shaping technique is a promising solution. In this paper, we propose a simple approach to realize the selective excitation of CARS spectra by shaping both the probe and pump pulses with the π phase step. By phase step modulation of the probe pulse, we show that the CARS signals between neighboring Raman energy levels can be greatly narrowed and differentiated, and then selective excitation can be realized by modulating both the probe and pump pulses. Finally, the mechanism of the selective excitation by population transfer is briefly discussed.
ACTIVE MODE-LOCKING IN DYNAMIC SYNC-BANDS
Authors: PARKHOMENKO Yu. N.
Published: May 2013

It is shown that active mode locking with regularized pulse trains can be implemented in two types of sync-bands. The analysis was executed with delay equations. In the sync-bands of the first type, regularization can be explained by increasing a "restoring force" of reproduced pulse states. The sync-bands of the second type are implemented near specific bifurcations where regularization is founded on essential deceleration of unstable temporal shifting processes. Effectiveness of the last laser mode is shown on the instance of the bifurcation of single pulses into two-pulse complexes.
SPATIOTEMPORAL STRONGLY NONLOCAL SPHERICAL LIGHT BULLETS
Authors: ZHONG WEI-PING
Published: May 2013

The general spherical beam solution of the three-dimensional (3D) spatiotemporal strongly nonlocal nonlinear (NN) Schrödinger equation in the form of light bullets is presented. The 3D spatiotemporal spherical beams are built by the products of generalized Laguerre polynomials and associated Legendre polynomials. By the choice of a specific integration constant, the spherical beam becomes an accessible soliton, which can exist in various forms. We confirm the existence and stability of these solutions by numerical simulations.
SYMMETRY PROPERTIES IN THE STUDY OF THE RAYLEIGH-TYPE OPTICAL MIXING SIGNAL IN PRESENCE OF A THERMAL BATH
Authors: PAZ J. L. , MASTRODOMENICO A. , IZQUIERDO M. A.
Published: May 2013

In this work are studied the symmetry properties of the Rayleigh-type optical mixing signal of a two-level molecular system immersed in a thermal bath and irradiated by a classical electromagnetic field. The solvent induces a random shift of the Bohr frequency in the molecular system. A methodology based in cumulant expansions is employed to obtain the average of the coherences, populations, and susceptibilities of Fourier components associated, calculated by the optical stochastic Bloch equations. These symmetry properties show the dependence of the measured spectra with the variations in the frequencies of the incident fields. Our results show that the inclusion of the thermal bath diminishes the intensity response as well it promotes the loss of the symmetry properties, compared with the same results in the absence of the bath.
INFLUENCES OF AGGREGATION ON THE TWO-PHOTON FLUORESCENCE PROCESS
Authors: ZHOU ZHIQIANG , LU CHANGGUI , CUI YIPING
Published: May 2013

Rhodamine B (RhB) is most often used as the reference in the two-photon induced fluorescence (TPIF) method to measure the two-photon absorption (TPA) cross-section. In this work, we investigate the influences of dimer formation, energy transfer and self-absorption on the two-photon fluorescence process. Those three effects will result in a large measurement error of the TPA cross-section. We thus provide a concentration gradient correction method by considering the above three processes to eliminate the measurement error.