Present state of the Aral Sea: diverging physical and biological characteristics of the residual basins.

Latest data on the hydrophysical and biological state of the residual basins of the Aral Sea are presented and compared. Direct, quasi-simultaneous observations were carried out in the central part of the Western Large Aral Sea, the northern extremity of the Large Aral known as Chernyshev Bay, Lake Tshchebas, and the Small Aral Sea in October 2014. The Large Aral Sea and Lake Tshchebas transformed into hyperhaline water bodies with highly special taxocene structure. The Small Aral Sea was a relatively diverse brackish ecosystem, which was rather similar to the pre-desiccation environment. The Small Aral Sea and Lake Tshchebas exhibited a fully-mixed vertical structure, whereas the Western Large Aral Sea was strongly stratified. Our data show that during desiccation, different parts of the Aral Sea experienced different environmental conditions, resulting in qualitative and quantitative differences in the physical and biological regimes among the different residual basins.

Pressure induced magnetic phase separation in La0.75Ca0.25MnO3 manganite.

The pressure dependence of the Curie temperature T(C)(P) in La(0.75)Ca(0.25)MnO(3) was determined by neutron diffraction up to 8 GPa, and compared with the metallization temperature T(IM)(P) (Postorino et al 2003 Phys. Rev. Lett. 91 175501). The behavior of the two temperatures appears similar over the whole pressure range, suggesting a key role of magnetic double-exchange also in the pressure regime where the superexchange interaction is dominant. The coexistence of antiferromagnetic and ferromagnetic peaks at high pressure and low temperature indicates a phase separated regime which is well reproduced with a dynamical mean-field calculation for a simplified model. A new P-T phase diagram has been proposed on the basis of the whole set of experimental data.

Microscopic study of a pressure-induced ferromagnetic-spin-glass transition in the geometrically frustrated pyrochlore (Tb1-xLax)2Mo2O7.

We have studied (Tb1-xLax)2Mo2O7 pyrochlores by neutron diffraction and muSR at ambient and under applied pressure. (Tb,La) substitution expands the lattice and induces a change from a spin-glass-like state (x=0) to a noncollinear ferromagnet (x=0.2). In the ferromagnetic structure, the Tb moments orient close to their local anisotropy axes as for an ordered spin ice, while the Mo ones orient close to the net moment. The temperature dependence of the muSR relaxation rates and static local fields suggests a second transition of dynamical nature below the Curie transition. Under pressure, the long range order breaks down and a spin-glass-like state is recovered. The whole set of data provides a microscopic picture of the spin correlations and fluctuations in the region of the ferromagnetic-spin-glass threshold.

Motor training in the manipulation of flexible objects in haptic environments.

A system with interchangeable constraints for studying skillful human movements via haptic displays is presented. It is shown how this system can be applied to the analysis of reaching movements in the manipulation of flexible objects. In the experiment, progress in arm motor training is considered for several subjects. Experimental data are obtained for slow, moderate, and fast movements. Future applications of the system and its limitations are discussed.

Pressure and field induced magnetic order in the spin liquid Tb2Ti2O7 as studied by single crystal neutron diffraction.

We have studied the spin liquid Tb2Ti2O7 by single crystal neutron diffraction under high pressure up to 2.8 GPa, together with uniaxial stress, down to 0.1 K, in zero and high magnetic fields up to 7 T. In zero magnetic field, a long-range ordered antiferromagnetic structure is induced by pressure. The Néel temperature and ordered magnetic moment can be tuned by the anisotropic pressure component. Under magnetic field, the antiferromagnetic structure transforms into a canted ferromagnetic one at 0.6 T. Spin canting persists even at 7 T. The magnetic phase diagram under pressure shows a strong increase of the Néel temperature with the field.

Direct determination of the magnetic structure of the delta phase of oxygen.

Simple diatomic molecules exhibit a variety of exciting physical phenomena under high pressures, including structural transitions, pressure induced metallization, and superconductivity. Oxygen is of particular interest because it carries a magnetic moment. For the first time we studied the magnetic structure in solid oxygen under very high pressure by a direct method, namely, neutron diffraction. A new type of magnetic order with ferromagnetic stacking of the antiferromagnetic O2 planes was discovered in delta-O2 at P=6.2 GPa. We show that all structural transformations at pressures <7 GPa are driven by spin interactions; therefore, high-pressure oxygen should be considered as a unique "spin-controlled crystal."

Local structure and glass transition of polybutadiene up to 4 GPa.

This communication presents a determination of the glass transition of polybutadiene under very high pressure, and raises the problem of the determination of the relative effects of temperature and density on the glass transition, depending on the pressure and temperature conditions. Local structure and slow dynamics were studied, by neutron scattering and calorimetry. To the best of our knowledge in neutron diffraction on soft matter such a high pressure, up to 4 GPa, was achieved.

Realistic Virtual Endoscopy of the ventricle system and haptic-based surgical simulator of hydrocefalus treatment.

New methods and software tools for automatic extraction of the ventricle system from magnetic resonance imagery (MRI) data, ventricle part classification, and realistic texturing are proposed to support Virtual Endoscopy (VE). Volume- and surface-based medical atlases are intensively used as templates in the methods. The processed ventricle-related surfaces are then utilized in a haptic-based system, which provides a surgeon with several basic functions simulating "virtual treatment" of hydrocephalus.

Pressure-induced crystallization of a spin liquid.

Liquids are expected to crystallize at low temperature. The only exception is helium, which can remain liquid at 0 K, owing to quantum fluctuations. Similarly, the atomic magnetic moments (spins) in a magnet are expected to order at a temperature scale set by the Curie-Weiss temperature theta(CW) (ref. 3). Geometrically frustrated magnets represent an exception. In these systems, the pairwise spin interactions cannot be simultaneously minimized because of the lattice symmetry. This can stabilize a liquid-like state of short-range-ordered fluctuating moments well below theta(CW) (refs 5-7). Here we use neutron scattering to observe the spin liquid state in a geometrically frustrated system, Tb(2)Ti(2)O(7), under conditions of high pressure (approximately 9 GPa) and low temperature (approximately 1 K). This compound is a three-dimensional magnet with theta(CW) = -19 K, where the negative value indicates antiferromagnetic interactions. At ambient pressure Tb(2)Ti(2)O(7) remains in a spin liquid state down to at least 70 mK (ref. 8). But we find that, under high pressure, the spins start to order or 'crystallize' below 2.1 K, with antiferromagnetic order coexisting with liquid-like fluctuations. These results indicate that a spin liquid/solid mixture can be induced by pressure in geometrically frustrated systems.

Transfer of free vascularized bone and skin-bone autografts: experiences in the application of external fixation apparatus.

The results of transfer of free vascularized bone and skin-bone autografts in 95 patients with defects (54) and nonunions (41) of tubular bones of different genesis are presented. In 71 cases, an external fixation apparatus was used for purposes of osteosynthesis. In 50 cases, the Ilizarov apparatus was applied prior to osteoplasty to correct deformity and fully or partially to correct a shortening of the extremity bone segment. In seven cases, lengthening of the bone segment was performed using an external fixation apparatus after osteoplastic reconstruction of the defect. Treatment was completed in 76 cases (80.0 percent); of these, the outcome was positive in 89.5 percent of cases. Failure was recorded in 10.5 percent of cases. The advantages of using an external fixation apparatus in combination with vascularized bone and osteocutaneous autografts are discussed.

[Errors and complications of plastic surgery of defects and false joints of the humerus using free vascularized bone autografts]. / Oshibki i oslozhneniia pri plastike defektov i lozhnykh sustavov plechevoi kosti svobodnymi vaskuliarizovannymi kostnymi autotransplantatami.

The authors analyse the errors and the complications in the plasty of defects and false joints of the humerus with free vascularized bone autografts in 20 patients aged 8-50 with the period of duration of the disease from 6 months to 9 years. The size of the defect was 3-20 cm (15 patients). In 17 cases a fibular bone graft on a vascular pedicle was used. In 8 patients 14 various kinds of complications occurred in different combinations. Non-union of one of the ends of the graft was observed most frequently (4) due to faults of osteosynthesis. In all patients consolidation was achieved. In this type of complications the authors advise to make an early repeated intervention with the aim of shortening the duration of treatment and subsequent rehabilitation. They stress the perspective character and the validity of this method of plasty, especially in extensive defects in association with poor vascularization of the injured segment of the extremity. Accurate performance of all stages of the intervention and the surgeon's personal experience play an important role in prevention of errors and complications in employing microsurgical technique in the treatment of this category of patients.

Restoration of the function of the cubital joint in extensive defects of bones and soft tissues using endoprosthesis and free skin grafts.

A new method of restoration of the function of the upper limb in extensive posttraumatic defects of bones and soft tissues of the cubital joint has been elaborated. The method is based on the excision of scar tissues with simultaneous implantation of the endoprosthesis of the K. M. Sivash type. The produced defect is covered by a free vascularized thoracodorsal skin-muscle transplant using the microstructural technique. Four operations have been performed so far. Clinical observations are reported. The method is efficient as it ensures reliable covering of the hinge part of the endoprosthesis by full-thickness skin, shortening the time of rehabilitation treatment 3-4 times and achieving more complete restoration of the function of the upper limb.

[Free bone and skin-bone autoplasty on a vascular pedicle in patients with defects and pseudarthroses]. / Svobodnaia kostnaia, kozhno-kostnaia autoplastika na sosudistoi nozhke u bol'nykh s defektami i lozhnymi sustavami.

Radical sequestr- and necrectomy followed by skin, bone or skin-bone autoplasty on the vascular pedicle with microvascular anastomoses between the autotransplant vessels and those of the extremity was successfully fulfilled in 16 patients with defects of tubular bones and false joints complicated by chronic osteomyelitis. The pedicled autografts were taken from the upper flaring portion of the ilium (13), from the fibula (2) and from the external surface of the femur (1). The two-step method of autoplasty is described.