Limits on the dependence of the fine-structure constant on gravitational potential from white-dwarf spectra.

We propose a new probe of the dependence of the fine-structure constant α on a strong gravitational field using metal lines in the spectra of white-dwarf stars. Comparison of laboratory spectra with far-UV astronomical spectra from the white-dwarf star G191-B2B recorded by the Hubble Space Telescope Imaging Spectrograph gives limits of Δα/α=(4.2±1.6)×10(-5) and (-6.1±5.8)×10(-5) from FeV and NiV spectra, respectively, at a dimensionless gravitational potential relative to Earth of Δφ≈5×10(-5). With better determinations of the laboratory wavelengths of the lines employed these results could be improved by up to 2 orders of magnitude.

Access related complications in anterior lumbar surgery performed by spinal surgeons.

PURPOSE: Anterior lumbar surgery is a common procedure for anterior lumbar interbody fusion (ALIF) and artificial disc replacement (ADR). Our aim was to study the exposure related complications for anterior lumbar spinal surgery performed by spinal surgeons. METHODS: A retrospective review was performed for 304 consecutive patients who underwent anterior lumbar spinal surgery over 10 years (2001-2010) at our institution. Each patient's records were reviewed for patients' demographics, diagnosis, level(s) of surgery, procedure and complications related to access surgery. Patients undergoing anterior lumbar access for tumour resection, infection, trauma and revision surgeries were excluded. RESULTS: All patients underwent an anterior paramedian retroperitoneal approach from the left side. The mean age of patients was 43 years (10-73; 197 males, 107 females). Indications for surgery were degenerative disc disease (DDD 255), degenerative spondylolisthesis (23), scoliosis (18), iatrogenic spondylolisthesis (5) and pseudoarthrosis (3). The procedures performed were single level surgery--L5/S1 (n = 147), L4/5 (n = 62), L3/4 (n = 7); two levels--L4/5 and L5/S1 (n = 74), L3/4 and L4/5 (n = 4); three levels--L3/4, L4/5, L5/S1 (n = 5); four levels--L2/3, L3/4, L4/5, L5/S1 (n = 5). The operative procedures were single level ADR (n = 131), a single level ALIF (n = 87) with or without posterior fusion, two levels ALIF (n = 54), two levels ADR (n = 14), a combination of ADR/ALIF (n = 10), three levels ALIF (n = 1), three levels ADR/ALIF/ALIF (n = 1), ADR/ADR/ALIF (n = 2), four levels ALIF (n = 1) and finally 3 patients underwent a four level ADR/ADR/ALIF/ALIF. The overall complication rate was 61/304 (20 %). This included major complications (6.2 %)--venous injury requiring suture repair (n = 14, 4.6 %) and arterial injury (n = 5 [1.6 %], 3 repaired, 2 thrombolysed). Minor complications (13.8 %) included venous injury managed without repair (n = 5, 1.6 %), infection (n = 13, 4.3 %), incidental peritoneal opening (n = 12, 3.9 %), leg oedema (n = 2, 0.6 %) and others (n = 10, 3.3 %). We had no cases of retrograde ejaculation. CONCLUSION: We report a very thorough and critical review of our anterior lumbar access surgeries performed mostly for DDD and spondylolisthesis at L4/5 and L5/S1 levels. Vascular problems of any type (24/304, 7.8 %) were the most common complication during this approach. The incidence of major venous injury requiring repair was 14/304 (4.6 %) and arterial injury 5/304 (1.6 %). The requirement for a vascular surgeon with the vascular injury was 9/304 (3 %; 5 arterial injuries; 4 venous injuries). This also suggests that the majority of the major venous injuries were repaired by the spinal surgeon (10/14, 71 %). Our results are comparable to other studies and support the notion that anterior access surgery to the lumbar spine can be performed safely by spinal surgeons. With adequate training, spinal surgeons are capable of performing this approach without direct vascular support, but they should be available if required.

Indications of a spatial variation of the fine structure constant.

We previously reported Keck telescope observations suggesting a smaller value of the fine structure constant α at high redshift. New Very Large Telescope (VLT) data, probing a different direction in the Universe, shows an inverse evolution; α increases at high redshift. Although the pattern could be due to as yet undetected systematic effects, with the systematics as presently understood the combined data set fits a spatial dipole, significant at the 4.2 σ level, in the direction right ascension 17.5 ± 0.9 h, declination -58 ± 9 deg. The independent VLT and Keck samples give consistent dipole directions and amplitudes, as do high and low redshift samples. A search for systematics, using observations duplicated at both telescopes, reveals none so far which emulate this result.

Rhabdias pseudosphaerocephala infection in Bufo marinus: lung nematodes reduce viability of metamorph cane toads.

Cane toads (Bufo marinus) were introduced to Australia in 1935 and have since spread widely over the continent, generating concern regarding ecological impacts on native predators. Most Australian cane toad populations are infected with lung nematodes Rhabdias pseudosphaerocephala, a parasite endemic to New World (native-range) cane toad populations; presumably introduced to Australia with its toad host. Considering the high intensities and prevalence reached by this parasite in Australian toad populations, and public ardour for developing a control plan for the invasive host species, the lack of experimental studies on this host-parasite system is surprising. To investigate the extent to which this lungworm influences cane toad viability, we experimentally infected metamorph toads (the smallest and presumably most vulnerable terrestrial phase of the anuran life cycle) with the helminth. Infected toads exhibited reduced survival and growth rates, impaired locomotor performance (both speed and endurance), and reduced prey intake. In summary, R. pseudosphaerocephala can substantially reduce the viability of metamorph cane toads.

Body mass index of girls in health influences menarche and skeletal maturation: a leptin-sympathetic nervous system focus on the trunk with hypothalamic asymmetric dysfunction in the pathogenesis of adolescent idiopathic scoliosis?

Lower body mass index (BMI) and lower circulating leptin levels have been reported in girls with AIS. In this paper we evaluate skeletal sizes and asymmetries by higher and lower BMI subsets about the means for each of three groups of girls age 11-18 years: 1) normals, 2) school screening referrals, and 3) preoperative girls. Higher and lower BMI subsets, likely to have separated subjects with higher from those with lower circulating leptin levels, identify: 1) girls with relatively earlier and later menarche; 2) trunk width size greater in the higher than in the lower BMI subset, of all three groups; 3) abnormal upper arm length (UAL) asymmetries (right minus left) in the lower BMI subset of the preoperative girls; and 4) in thoracic AIS of screened and preoperative girls, Cobb angle and apical vertebral rotation each significantly and positively correlate with UAL asymmetry in the lower BMI subset but not in the higher BMI subset. In preoperative girls, the lower BMI subset shows the combination of relatively reduced pelvic width and abnormal UAL asymmetry, suggesting that both are linked to lower circulating leptin levels. An earlier puberty with hormonal changes provides a plausible explanation for the larger trunk width at the shoulders and pelvis especially at the younger ages in the higher BMI subsets. At the shoulders, this widening is driven by the ribcage which, in human evolution was acquired with decoupling of head and trunk movements required for efficient bipedal gait. The UAL asymmetry patterns within the groups and BMI subsets are not explained by hormonal mechanisms. It is hypothesized that 1) normal trunk widening of the thoracic cage by hormones in human adolescence is supplemented via the sympathetic nervous system under leptin-hypothalamic control influenced by energy stores (metabolic fuel); and 2) hypothalamic dysfunction with altered hypothalamic sensitivity to leptin through a SNS-driven asymmetric effect may create skeletal length asymmetries in upper arms, ribs, ilia and vertebrae, and initiate AIS. Additional mechanisms acting in the spine and trunk may be required for AIS to progress including 1) somatic nervous system dysfunction, 2) biomechanical spinal growth modulation, and 3) osteopenia.

Ultrasound femoral anteversion (FAV) relative to tibial torsion (TT) is abnormal after school screening for adolescent idiopathic scoliosis (AIS): evaluation by two methods.

In the scoliotic spine, torsion is generally evaluated in relation to axial rotation of the apical vertebra. In the lower limbs, the changes in torsion by age of femoral anteversion (FAV) relative to tibial torsion (TT) have been studied in dried bones, normal growing subjects and adults and subjects with osteoarthritis of the hip or the knee. This paper reports the application of real-time ultrasound to FAV and TT in normal children age 11-18 years and in scoliosis screening referrals with particular reference to how FAV relates to TT as 1) ratios, and 2) tibio-femoral index (TFI) of torsion, calculated as TT minus femoral FAV. The FAV/TT ratio findings show an abnormal normal relationship of FAV to TT both proximo-distally and in left-right asymmetry. These may express torsional abnormalities in femoral and/or tibial growth plates with left-right asynchrony suggesting the possibility of similar torsional abnormalities in vertebral end-plates and/or rib growth plates initiating the deformity of AIS. TFI of the right limb in the scoliosis girls is greater than in the normals that is interpreted as resulting from earlier skeletal maturation of FAV. FAV/TT ratios and TFI are unrelated to the spinal deformity (Cobb angle and apical vertebral rotation) except for boys where TFI is associated with apical vertebral rotation. FAV/TT ratios may be a more accurate method estimating the relationship of FAV to TT. than TFIs.

Leg-arm length ratios correlate with severity of apical vertebral rotation in girls after school screening for adolescent idiopathic scoliosis (AIS): a dynamic pathomechanism in the initiation of the deformity?

There is increasing support for the view that the unique human bipedalism and the erect posture are prerequisites for the pathogenesis of adolescent idiopathic scoliosis (AIS). How human bipedalism may contribute to the pathogenesis of AIS is not clear. In normal humans, axial rotations and counter-rotations of the trunk are carried out frequently and forcibly in activities that are not performed by quadrupeds. Some workers have analysed gait in AIS subjects, others have studied torsions in lower limb bones, but there are only two reports on leg-arm ratios in relation to AIS. In this paper, leg-arm ratios studied in relation to the spinal deformity in scoliosis screening referrals, reveal a highly significant correlation with the apical vertebral rotation but not the Cobb angle of the scoliosis curves. We suggest that leg-arm proportions and movements during gait involving pelvi-spinal axial rotations and thoracic counter-rotations contribute a dynamic pathomechanism to early AIS from whatever cause and involving the thoracic cage. Curve progression needs other mechanisms that may include a central nervous system failure to control structural asymmetry of vertebral axial rotation, and biomechanical spinal growth modulation.

Ultrasound femoral anteversion (FAV) and tibial torsion (TT) after school screening for adolescent idiopathic scoliosis (AIS).

Torsion and counter-torsion in the spine are features of the three-dimensional deformity of adolescent idiopathic scoliosis, Vertebral axial rotation has recently been found in the normal adult thoracic spine. Torsion in the lower limbs, femora and tibiae is a feature of normal human skeletal postnatal development. In recent years, femoral anteversion (FAV) and tibial torsion (TT) have been studied in normal children by imaging techniques, especially ultrasound. This paper reports summaries of the application of real-time ultrasound to FAV and TT of normal children and scoliosis school screening referrals. In the scoliosis girls and boys, the FAV decrease and FAV asymmetry compared with normals may result from abnormally increased femoral detorsion maturationally earlier with left-right asynchrony which, if repeated as a growth plate anomaly in the trunk (spine and/or periapical ribs), might initiate the AIS deformity, given other requirements. In scoliosis boys relative to girls, the TT decrease without asymmetry may result from sexually dimorphic maturation at knee tibial growth plates ? maturationally delayed TT with left-right synchrony.

Coulter counter-based evaluation of sperm volume to assess sperm viability of bull semen and application to X/Y sperm sorting.

The Coulter Counter Hypo-Osmotic Swelling test (CC-HOS) was developed to provide insight into the membrane integrity (relative volume shift Vr) of sperm necessary for fertilization, and to identify the optimum buffer needed for the X/Y chromosome sorting process. Using the CC-HOS test on neat bovine semen, the mean relative volume shift Vr for July and August was 1.20 and 1.14, respectively, whereas mean Vr values ranged from 1.32 to 1.41 during September to November. There was an inverse relationship between Vr magnitude and environmental temperature; we inferred that this enhanced sperm viability during autumn relative to summer. A method was developed to measure the dynamics of volume change of sperm in the buffer (pH 6.5) used for the X/Y chromosome sorting process. When exposed to the buffer (4 mM K+, 153 mM Na+, 140 mM Cl(-)), sperm from Bull C had a mean modal volume of 22.8+/-0.2 fL during a 0-300 s time interval, which did not significantly vary from sperm volumes (21.88+/-0.66 fL for Bull A and 22.46+/-0.38 fL for Bull B) noted in isotonic Isoton II solution. However, when exposed to lower ionic concentrations (2 mM K+, 62 mM Na+, 47 mM Cl-), the mean volume of Bull C sperm increased to 29.2+/-1.5 fL and exhibited slower rates toward stabilized volumes relative to higher ionic concentration buffers. Utilization of volume swelling measurements for measuring the impact of ion concentrations in X/Y chromosome sorting process buffers illustrated the importance of its application for emerging sperm-based biotechnologies.

Patterns of extra-spinal left-right skeletal asymmetries in adolescent girls with lower spine scoliosis: relative lengthening of the ilium on the curve concavity & of right lower limb segments.

Extra-spinal skeletal length asymmetry have been reported for the upper limbs and periapical ribs of patients with thoracic adolescent idiopathic scoliosis. This paper reports (1) a third pattern with relative lengthening of the ilium on the concavity of lower spine scolioses, and (2) a fourth pattern of relative lengthening of the right total leg and right tibia unrelated statistically to the severity or side of lower spinal scolioses. The findings pose the question: are these anomalous extra-spinal left-right skeletal length asymmetries unconnected with the pathogenesis of AIS. Or, are they indicative of what may also be happening to some vertebral physes as an initiating pathogenic mechanism for the scoliosis?

Left-right upper arm length asymmetry associated with apical vertebral rotation in subjects with thoracic scoliosis: anomaly of bilateral symmetry affecting vertebral, costal and upper arm physes?

Left-right skeletal length asymmetries in upper limbs related to curve side and severity have been detected with adolescent idiopathic scoliosis (AIS). This paper reports upper arm length asymmetry in thoracic scoliosis related significantly to apical vertebral rotation in school screening referrals. The reason(s) for the association of upper arm length asymmetry with apical vertebral rotation is unknown and three factors are considered: (1) neuromuscular mechanisms from primary or secondary causes, (2) relative concave neurocentral synchondrosis overgrowth, and (3) relative concave periapical rib length overgrowth, A putative anomaly of growth plates (physes) of ribs, neurocentral synchondroses and upper arms, would account for the findings. A solution to this dilemma may emerge from the results of surgery should concave periapical rib resections become evaluated further for right thoracic AIS in girls.

Etiologic theories of idiopathic scoliosis: neurodevelopmental concept of maturational delay of the CNS body schema ("body-in-the-brain").

Several workers consider that the etiology of adolescent idiopathic scoliosis (AIS) involves undetected neuromuscular dysfunction. During normal development the central nervous system (CNS) has to adapt to the rapidly growing skeleton of adolescence, and in AIS to developing spinal asymmetry from whatever cause. Examination of evidence from (1) anomalous extra-spinal left-right skeletal length asymmetries, (2) growth velocity and curve progression, and (3) the CNS body schema, parietal lobe and temporoparietal junction, led us to propose a new etiologic concept namely of delay in maturation of the CNS body schema during adolescence. In particular, the development of an early AIS deformity at a time of rapid spinal growth the association of CNS maturational delay results in the CNS attempting to balance a lateral spinal deformity in a moving upright trunk that is larger than the information on personal space (self) already established in the brain by that time of development. It is postulated that the CNS maturational delay allows scoliosis curve progression to occur - unless the delay is temporary when curve progression would cease. The putative maturational delay in the CNS body schema may arise (1) from impaired sensory input: (2) primarily in the brain; and/or (3) from impaired motor output. Oxidative stress with lipid peroxidation in the nervous system may be involved in some patients. The concept brings together many findings relating AIS to the nervous and musculo-skeletal systems and suggests brain morphometric studies in subjects with progressive AIS.

Patterns of extra-spinal left-right skeletal asymmetries and proximo-distal disproportion in adolescent girls with lower spine scoliosis: ilio-femoral length asymmetry & bilateral tibial/foot length disproportion.

Anomalous extra-spinal left-right skeletal length asymmetries have been detected in girls with adolescent idiopathic (AIS) in four sites (1) upper limbs, (2) periapical ribs, (3) ilium, and (4) right leg and right tibia. This paper on adolescent girls with lower spine scoliosis reports (1) a fifth pattern of left-right ilio-femoral length asymmetry associated with sacral alar height asymmetry, and (2) bilateral anomalous lengthening of the tibia relative to the foot. The findings are consistent with the hypothesis that at the time of diagnosis of AIS in girls there are anomalies of skeletal proportions associated with a predisposition to curve progression; these proportions are in three dimensions--left-right, cephalo-caudal in the trunk (proximo-distal in the lower limbs), and front-back in the trunk. The origin of these anomalies is unknown but possible causes, and of the associated AIS, are genetic and environmental factors acting in embryonic life not expressed phenotypically until years after birth.

Etiologic theories of idiopathic scoliosis: the breaking of bilateral symmetry in relation to left-right asymmetry of internal organs, right thoracic adolescent idiopathic scoliosis (AIS) and vertebrate evolution.

In the search to understand the etiology and pathogenesis of adolescent idiopathic scoliosis (AIS) some workers have focused on mechanisms initiated in embryonic life including a disturbance of bilateral (left-right or mirror-image) symmetry highly conserved in vertebrates. The normal external bilateral symmetry of vertebrates results from a default process involving mesodermal somites. The normal internal asymmetry of the heart, major blood vessels, lungs and gut with its glands is also highly conserved among vertebrates. It results from the breaking of the initial bilateral symmetry by a binary asymmetry switch mechanism producing asymmetric gene expression around the embryonic node and/or in the lateral plate mesoderm. In the mouse this switch occurs during gastrulation by cilia driving a leftward flow of fluid and morphogen(s) at the embryonic node (nodal flow) that favors precursors of the heart, great vessels and viscera on the left. Based on the non-random laterality of thoracic AIS curves, the hypothesis is suggested that an anomaly of the binary asymmetry switch explains the excess of right/left thoracic AIS. Some support for this hypothesis is the prevalence of right and left scoliosis curve laterality associated with situs inversus. There is recent evidence that vertebrates within their bilateralised shell retain an archaic left-right asymmetric visceral body organization evident in thoracic and abdominal organs.

Etiologic theories of idiopathic scoliosis: enantiomorph disorder concept of bilateral symmetry, physeally-created growth conflicts and possible prevention.

The detection of anomalous extra-spinal left-right skeletal length asymmetries in the upper limbs, periapical ribs, ilia and lower limbs of subjects with adolescent idiopathic scoliosis (AIS) raises questions about skeletal bilateral symmetry of vertebrates in health and disorder, its origin and control. The vertebrate body plan externally has mirror-image bilateral symmetries that are highly conserved culminating in the adult form. The normal human body can be viewed as containing paired skeletal structures in the axial and appendicular skeleton as 1) separate left and right paired forms (eg long limb bones, ribs, ilia), and 2) united in paired forms (eg vertebrae, sternum, skull, mandible). Each of these separate and united pairs are mirror-image forms--enantiomorphs. Left-right asymmetries of growth plates (physes) may cause (1) in long bones length asymmetries, (2) within one or more vertebral physes putative growth conflict with distortion as deformity, and (3) between ribs and vertebrae putative growth conflict that triggers thoracic AIS suggesting preventive surgery on spine and ribs. There is evidence of a possible role for environmental factors in AIS development. Genes and the environment (nature/nurture) may interact pre- and/or post-natally to explain both the deformity of AIS and its association with widespread anomalous skeletal length asymmetries. If substantiated there may ultimately be a place for the prevention of AIS in some subjects.

Limits on variations in fundamental constants from 21-cm and ultraviolet Quasar absorption lines.

Quasar absorption spectra at 21-cm and UV rest wavelengths are used to estimate the time variation of x [triple-bond] alpha(2)g(p)mu, where alpha is the fine structure constant, g(p) the proton g factor, and m(e)/m(p) [triple-bond] mu the electron/proton mass ratio. Over a redshift range 0.24 < or = zeta(abs) < or = 2.04, (Deltax/x)(weighted)(total) = (1.17 +/- 1.01) x 10(-5). A linear fit gives x/x = (-1.43 +/- 1.27) x 10(-15) yr(-1). Two previous results on varying alpha yield the strong limits Deltamu/mu = (2.31 +/- 1.03) x 10(-5) and Deltamu/mu=(1.29 +/- 1.01) x10(-5). Our sample, 8 x larger than any previous, provides the first direct estimate of the intrinsic 21-cm and UV velocity differences 6 km s(-1).

Scoliosis in association with infantile hypophosphatasia: a case study in two siblings.

STUDY DESIGN: A case study of scoliosis in two siblings with infantile hypophosphatasia and review of literature are presented. OBJECTIVES: To report the rare occurrence of scoliosis in two siblings with infantile hypophosphatasia and detail problems in the surgical management of scoliosis in this rare disease. SUMMARY OF BACKGROUND DATA: To the authors' knowledge there is only one reported case of scoliosis in infantile hypophosphatasia. However, there is no report describing the nature of the curve, its progression, or the surgical management of scoliosis in infantile hypophosphatasia. METHODS: The first sibling was diagnosed shortly after birth to have scoliosis that progressed rapidly despite brace treatment. At 4 years, he underwent anterior convex arthrodesis and posterior T6-L1 Luque trolley stabilization. Because of further curve progression, he had to undergo corrective anterior and posterior osteotomies, stabilization, and fusion at 11 years of age. The second sibling was diagnosed to have scoliosis at the age of 3 years and underwent anterior thoracoscopic release and posterior Luque trolley stabilization. RESULTS: The first sibling with a mild form of infantile hypophosphatasia had to undergo multiple procedures to attain fusion and arrest of curve progression. The second sibling with a severe variety of infantile hypophosphatasia surprisingly attained a spontaneous fusion of the curve following the initial correction and stabilization with no further progression at 9-year follow-up. CONCLUSIONS: Curve progression and fusion rates following scoliosis correction are not related to the disease severity or biochemical findings. These rapidly progressive curves are amenable to surgical correction despite the unfavorable metabolic nature of the disease. Hypercalcemia and seizures responding to pyridoxine are complications in the postoperative period of which the surgeon should be aware.