Change In Handedness Research Articles

Fifty Years of Handedness Research: A Neurological and Methodological Update.

Handedness, a complex human aspect that reflects the functional lateralization of the hemispheres, also interacts with the immune system. This study aimed to expand the knowledge of the lateralization of hand, foot, and eye activities in patients with immune-mediated (IM) or other (noIM) neurological diseases and to clarify the properties of the Edinburgh Handedness Inventory (EHI) in an Italian population. Three hundred thirty-four patients with IM or noIM diseases affecting the brain or spine and peripheral nervous system were interviewed about stressful events preceding the disease, subjective handedness, and familiarity for left-handedness or ambidexterity. The patients and 40 healthy subjects underwent EHI examination. In the whole group of participants, 24 items of the EHI were classified into five factors (Hand Transitive, Hand Refined, Hand Median, Foot, Eye), demonstrating good reliability and validity. Chronological age had a significant influence on hand and foot EHI factors and the laterality quotient (LQ), particularly on writing and painting. In the patient groups, EHI factors and the LQ were also predicted by age of disease onset, duration of disease, and family history of left-handedness or ambidexterity. No differences were found between patients and healthy subjects, but pencil use scored significantly lower in patients with IM diseases than in those with noIM brain diseases. These results demonstrate that the lateralization of hand and foot activities is not a fixed human aspect, but that it can change throughout life, especially for abstract and symbolic activities. Chronic neurological diseases can cause changes in handedness. This may explain why, unlike systemic immunological diseases, IM neurological diseases are not closely associated with left-handedness. In these patients, the long version of the EHI is appropriate for determining the lateralization of body activities to contextualize the neurological picture; therefore, these findings extend the Italian normative data sets.

Structural changes in chromosomes driven by multiple condensin motors during mitosis

We create a computational framework that utilizes loop extrusion (LE) by multiple condensin I/II motors to predict changes in chromosome organization during mitosis. The theory accurately reproduces the experimental contact probability profiles for the mitotic chromosomes in HeLa and DT40 cells. The LE rate is smaller at the start of mitosis and increases as the cells approach metaphase. Condensin II-mediated mean loop size is about six times larger than loops because of condensin I. The loops, which overlap each other, are stapled to a central dynamically changing helical scaffold formed by the motors during the LE process. A polymer physics-based data-driven method that uses the Hi-C contact map as the only input shows that the helix is characterized as random helix perversions (RHPs) in which the handedness changes randomly along the scaffold. The theoretical predictions, which are testable using imaging experiments, do not contain any parameters.

Childhood ischaemic stroke in the basal ganglia can lead to fine motor and anxiety disorders: a retrospective analysis and follow-up of 109 cases

BackgroundStroke in children easily causes long-term dysfunction. Whether the prognoses of motor and anxiety disorders are related to the affected stroke area has not been reported.MethodsOne hundred nine cases of children with ischaemic stroke were reviewed and divided into three groups: lenticular nucleus lesions only (lenticular nucleus group), lenticular nucleus and caudate head lesions (caudate head group), and lenticular nucleus and thalamus lesions (thalamus group). Overall prognosis was evaluated by the mRS score. The SCAS-P was used to evaluate anxiety in children aged ≥6 years.ResultsmRS scores were ≤ 2 points (mean: 0.62), no significant difference among groups. 3/21 (14.2%) patients in the caudate head group changed handedness, which is significantly higher than other groups. Patients with lesions in thalamus group had significantly higher SCAS-P scores.ConclusionsThe overall prognosis of children with basal ganglia ischaemic stroke is good. However, hand preference changes and anxiety disorders may develop. Patients in the caudate head groups are more likely to suffer from fine motor disorders and changes in handedness. Patients within the thalamus group are more prone to anxiety than patients in the other groups. Anxiety disorders should be noted in children with basal ganglia stroke.

Hydrogen-Bonded One-Dimensional Chains of Quinacridone on Ag(100) and Cu(111): The Role of Chirality and Surface Bonding

The adsorption and ordering of the prochiral molecule quinacridone (QA) on the Ag(100) and Cu(111) surfaces were studied by low-energy electron diffraction and scanning tunneling microscopy. Upon adsorption, the molecules form parallel homochiral chains of flat-lying molecules linked together via hydrogen bonds on both surfaces, but these chains show significant surface-dependent differences concerning their lateral order. On both substrates, the chains are not thermodynamically stable but only metastable and stabilized by kinetic barriers. On the Ag(100) surface, annealing induces a phase transition to a highly ordered and heterochiral structure with a reduced density of hydrogen bonds. The related loss of bonding energy is overcompensated by a stronger bonding to the substrate, yielding a commensurate structure. For QA on Ag(100), we propose that during the initial chain formation and the phase transition upon annealing, the molecules can change their handedness by rotating around their long axes. In contrast, the initial chain formation and the phase transitions of QA on the Cu(111) surface appear to be subject to stronger kinetic limitations. These are explained by stronger substrate molecule interactions on Cu(111), which reduce the diffusion and the possibility for a change of handedness in comparison to QA on Ag(100). We discuss how the intermolecular hydrogen bonds, the 2D chirality, and the different chemical reactivities of the two surfaces [Ag(100) and Cu(111)] influence the structural formation of QA aggregates. We compare our results to the results for QA on Ag(111) reported previously by Wagner et al. [JPCC 2014, 118, 10911-10920].

MreB5 Is a Determinant of Rod-to-Helical Transition in the Cell-Wall-less Bacterium Spiroplasma

In most rod-shaped bacteria, the spatial coordination of cell wall synthesis machinery by MreBs is the main theme for shape determination and maintenance in cell-walled bacteria [1-9]. However, how rod or spiral shapes are achieved and maintained in cell-wall-less bacteria is currently unknown. Spiroplasma, a helical Mollicute that lacks cell wall synthesis genes, encodes five MreB paralogs and a unique cytoskeletal protein fibril [10, 11]. Here, we show that MreB5, one of the five MreB paralogs, contributes to cell elongation and is essential for the transition from rod-to-helical shape in Spiroplasma. Comparative genomic and proteomic characterization of a helical and motile wild-type Spiroplasma strain and a non-helical, non-motile natural variant helped delineate the specific roles of MreB5. Moreover, complementation of the non-helical strain with MreB5 restored its helical shape and motility by a kink-based mechanism described for Spiroplasma [12]. Earlier studies had proposed that length changes in fibril filaments are responsible for the change in handedness of the helical cell and kink propagation during motility [13]. Through structural and biochemical characterization, we identify that MreB5 exists as antiparallel double protofilaments that interact with fibril and the membrane, and thus potentially assists in kink propagation. In summary, our study provides direct experimental evidence for MreB in maintaining cell length, helical shape, and motility-revealing the role of MreB in sculpting the cell in the absence of a cell wall.

The Solar Neutrino Problem as Evidence of New Interaction

A new concept is proposed to solve the solar neutrino problem, that is based on a hypothesis about the existence of a new interaction of electron neutrinos with nucleons mediated by massless pseudoscalar bosons. At every collision of a neutrino with nucleons of the Sun, its handedness changes from left to right and vice versa, and its energy decreases. The postulated hypothesis, having only one free parameter, provides a good agreement between the calculated and experimental characteristics of all five observed processes with solar neutrinos.

Hand Preference and Performance in Basketball Tasks.

The aims of this study were to develop and validate an instrument to quantitatively assess the handedness of basketballers in basketball tasks (Basketball Handedness Inventory, BaHI) and to compare it with their handedness in daily activities by the Edinburgh Handedness Inventory (EHI). The participants were 111 basketballers and 40 controls. All subjects completed the EHI and only basketballers filled in the BaHI. To validate the BaHI, a voluntary subsample of basketballers repeated the BaHI. Exploratory and confirmatory factor analyses supported a two-factor model. Our results show that: (i) Handedness score (R) in daily actions did not differ between basketball players (R by EHI = 69.3 ± 44.6) and the control group (R by EHI = 64.5 ± 58.6); (ii) basketballers more frequently favored performing certain sport tasks with the left hand or mixed hands (as highlighted by R by BaHI = 50.1 ± 47.1), although their choice was primarily the right hand in everyday gestures; and (iii) this preference was especially true for athletes at the highest levels of performance (R by BaHI of A1 league = 38.6 ± 58.3) and for those playing in selected roles (point guard’s R = 29.4 ± 67.4). Our findings suggest that professional training induces handedness changes in basketball tasks. The BaHI provides a valid and reliable measure of the skilled hand in basketball. This will allow coaches to assess mastery of the ball according to the hand used by the athlete in the different tasks and roles.

Magneto-optical Kerr effect and nuclear resonant scattering study of uni-directional anisotropy in hard-soft magnetic bilayers

The present work reports the unconventional exchange bias (EB) phenomena in an exchange-coupled hard and soft magnetic bilayer system and the tunability of EB. The EB phenomena, i.e., shifting of the hysteresis loop of the soft (Fe) layer is observed when the hard magnetic (L10 FePt) layer is under the remanent state indicating the development of unidirectional anisotropy. The nuclear resonant scattering measurements clearly reveal the development of unidirectional anisotropy in the soft magnetic (Fe) layer, when the hard magnetic layer is under the remanent state. The magnetization reversal process is investigated by measuring two in-plane orthogonal components of magnetization, i.e., parallel (M∥) and perpendicular (M⊥) to the applied field using the magneto-optical Kerr effect (MOKE). When the magnetic field is applied parallel (antiparallel) to the biasing field direction, (HSAT) magnetization reversal is nonuniform, and on the other hand, the rotation of magnetization is observed when the magnetic field is applied away from the HSAT direction. In addition, the sign inversion of the M⊥ component is observed when the magnetic field is applied at the same angle on either side of the HSAT direction, which clearly imply the change in handedness of the chirality of spin structure during the magnetization reversal of the soft layer. Further, it is observed that the EB decreases with the increase of soft magnetic (Fe) layer thickness, demonstrating the tunable nature of EB phenomena even in these unconventional systems.

Universal optical control of chiral superconductors and Majorana modes

Chiral superconductors are a novel class of unconventional superconductors that host topologically protected chiral Majorana fermions at interfaces and domain walls, elusive quasiparticles that could serve as a platform for topological quantum computing. Here we show that, in analogy to a qubit, the out-of-equilibrium superconducting state in such materials can be described by a Bloch vector and controlled on ultrafast time scales. The all-optical control mechanism is universal, permitting arbitrary rotations of the order parameter, and can induce a dynamical change of handedness of the condensate. It relies on transient breaking of crystal symmetries via choice of pulse polarization to enable arbitrary rotations of the Bloch vector. The mechanism extends to ultrafast time scales, and importantly the engineered state persists after the pump is switched off. We demonstrate that these phenomena should appear in graphene or magic-angle twisted bilayer graphene (TBG), as well as Sr$_2$RuO$_4$, as candidate chiral $d+id$ and $p+ip$ superconductors, respectively. Furthermore, we show that chiral superconductivity can be detected in time-resolved pump-probe measurements. This paves the way towards a robust mechanism for ultrafast control and measurement of chirally-ordered phases and Majorana modes.

Hand Preference Develops Across Childhood and Adolescence in Extremely Preterm Children: The EPICure Study

AimWe attempted to determine how handedness changes with age and its relation to brain injury and cognition following birth before 26 weeks of gestation. MethodsWe used data from the EPICure study of health and development following birth in the British Isles in 1995. Handedness was determined by direct observation during standardized testing at age 2.5, six, and 11 years and by self-report using the Edinburgh Handedness Inventory at 19 years. Control data from term births were included at six, 11, and 19 years. ResultsIn extremely preterm children left handedness increased from 9% to 27% between 2.5 and 19 years, with a progressive reduction in mixed handedness from 59% to 13%. Although individual handedness scores varied over childhood, the between-group effects were consistent through 19 years, with greatest differences in females. In extremely preterm participants, neonatal brain injury was associated with lower right handedness scores at each age and left-handed participants had lower cognitive scores at 19 years after controlling for confounders, but not at other ages. ConclusionIncreasing hand lateralization is seen over childhood in extremely preterm survivors, but consistently more individuals have non-right preferences at each age than control individuals.

Is it possible to change handedness after only a short period of practice? Effects of 15 days of intensive practice on left-hand writing in strong right-handers

ABSTRACTPrevious studies have argued that a person’s ability to write legibly with the non-dominant hand after a limited amount of practice suggests that manual skill can be easily transferred. The present study investigated the degree to which handedness can be altered by short-term practice on the highly complex manual activity of handwriting. Nine strongly right-handed individuals practiced writing with their left hand daily for 15 consecutive days. On three occasions, at baseline, at the end of the practice period and after a one-month retention interval, the similarity of left- and right-hand writing was inspected and handedness was tested by means of the Purdue Pegboard as well as handedness questionnaires. All participants demonstrated more legible writing with their left hand after practice, and the writing was more similar to that of their preferred, right-hand writing, although to different degrees. Pegboard performance improved with the left hand, but equally as much with the right, and there were no other changes in participants’ manual preference patterns. The findings of the present study do not indicate any degree of change in handedness, outside the impressive progress in left-hand writing. The large inter-individual variability, suggests that further research should focus on more individual analyses.

Investigating the Handedness Dynamics of Tetrasomes

Nucleosomes formed by DNA wrapping around histone octamers are the basic compaction unit of eukaryotic chromatin. Besides packaging DNA, they also play an essential role in genome regulation by controlling DNA accessibility. Their assembly follows a precise pathway in which first tetramers of H3 and H4 histones bind to DNA, forming tetrasomes, and then two dimers of H2A and H2B histones complete the formation of full nucleosomes. Here, we present our single-molecule studies on the assembly of tetrasomes by directly measuring the length, twist, and torque of single DNA molecules using Freely Orbiting Magnetic Tweezers (FOMT) and electro-Magnetic Torque Tweezers (eMTT). By this means, we have investigated both the replication-coupled histone H3.1 and its replication-independent variant histone H3.3. Our results indicate that tetrasomes exhibit a spontaneous flipping between a preferentially occupied left-handed state (ΔLk = −0.73) and a less populated right-handed state (ΔLk = +1.0), while weak torques convert them from one state into the other. In addition, the stepwise assembly of full nucleosomes suggests that tetrasomes undergoing changes in handedness remain viable intermediates. We further show how studies performed on tetrasomes that are artificially modified at their H3-H3 interface provide more insight into their handedness dynamics. Our findings reveal dynamical rearrangements of the nucleosomal structure that illustrate how chromatin could regulate DNA-supercoiling.

Handedness change after dominant side amputation: Evaluation from a hand laterality judgment task.

Amputation of the dominant hand forces patients to use their non-dominant hand exclusively. Whether this chronic forced use of the non-dominant hand would affect the handedness preference remains an open question. In this study, the handedness preference in amputees was evaluated using a hand laterality judgment task by comparing recognition speeds of their lost hand and remaining hand. A handedness index was defined as lateralization between response times to the left hand and the right hand. Healthy controls responded faster to the pictures of dominant hand than that of non-dominant hand, while amputees did not show this handedness advantage. The handedness index was significantly correlated to the response time, accuracy, amputation age and the time post amputation. Amputees with poorer performance experienced severer handedness change and new amputees were more likely to suffer handedness change. Our results suggest that handedness is changed after dominant side amputation and the handedness change might not be induced by chronic use of the intact hand.

Supramolecular assembly of achiral alkynylplatinum(II) complexes and carboxylic β-1,3-glucan into different helical handedness stabilized by Pt⋅⋅⋅Pt and/or π-π interactions.

Two-component ensembles of alkynylplatinum(II) terpyridine (tpy) complexes and carboxylic β-1,3-glucan (CurCOOH) have been investigated by using spectroscopic and microscopic techniques, as well as time-dependent UV/Vis absorption and circular dichroism (CD) experiments. Microscopic images of [Pt(tpy){C≡CC6 H4 (CH2 NMe3 -4)}](OTf)2 (1) have revealed spherical nanostructures, whereas helical fibrous structures of different lengths, depending on the concentration of complex 1 and CurCOOH, were observed. The helical assemblies have been found to show low-energy metal-metal-to-ligand charge transfer (MMLCT) absorption and triplet MMLCT ((3) MMLCT) emission, which are indicative of Pt⋅⋅⋅Pt and/or π-π interactions between the complex 1 molecules. Interestingly, the ensemble has been demonstrated to show different handedness and even a change in handedness over time under different experimental conditions. Low temperatures, low concentrations of CurCOOH, high concentrations of complex 1, or successive addition of CurCOOH into complex 1 solution favor the formation of right-handed helical assemblies, whereas high temperatures, high concentrations of CurCOOH, low concentrations of complex 1, or single-batch addition of CurCOOH into complex 1 solution result in a fast chiroptical inversion of the ensemble solution, giving rise to the left-handed helical assemblies as the dominant species. The results have been rationalized by considering the competing kinetically and thermodynamically controlled assembly-elongation of the ensemble, which leads to the formation of right-handed and left-handed helical assemblies, respectively. The change in the handedness of the ensemble has been demonstrated to stem from the formation of two-component assemblies with supramolecular interactions, in contrast to the template- induced chiral amplification commonly observed in other systems.

Color-Coding Point Group & Space Group Diagrams and other Mathematical Journeys

Color clarifies diagrams point group and space group diagrams. For example, consider the general position diagrams and the symbol diagrams. Symmetry operations can be represented by matrices whose determinant is either plus one or minus one. In the former case there is no change of handedness and in the latter case there is a change of handedness. The general position diagrams emphasis this information by color-coding. The symbol diagrams are a little more complicated and will be demonstrated. The second topic is a comparison of the thirty-two three-dimensional point groups with their corresponding 18 abstract mathematical groups. The corresponding trees will be explored. This discussion leads into the topic of irreducible representations.

Polymorphism Complexity and Handedness Inversion in Serum Albumin Amyloid Fibrils

Protein-based amyloid fibrils can show a great variety of polymorphic structures within the same protein precursor, although the origins of these structural homologues remain poorly understood. In this work we investigate the fibrillation of bovine serum albumin--a model globular protein--and we follow the polymorphic evolution by a statistical analysis of high-resolution atomic force microscopy images, complemented, at larger length scales, by concepts based on polymer physics formalism. We identify six distinct classes of coexisting amyloid fibrils, including flexible left-handed twisted ribbons, rigid right-handed helical ribbons and nanotubes. We show that the rigid fibrils originate from flexible fibrils through two diverse polymorphic transitions, first, via a single-fibril transformation when the flexible left-handed twisted ribbons turn into the helical left-handed ribbons, to finally evolve into nanotube-like structures, and second, via a double-fibril transformation when two flexible left-handed twisted ribbons wind together resulting in a right-handed twisted ribbon, followed by a rigid right-handed helical ribbon polymorphic conformation. Hence, the change in handedness occurs with an increase in the level of the fibril's structural organization.

Heterochiral Domain Formation in Homochiral α-Dipalmitoylphosphatidylcholine (DPPC) Langmuir Monolayers at the Air/Water Interface

α-Dipalmitoylphosphatidylcholine (DPPC) Langmuir monolayers at the air/water interface are an important biomimetic system. Previous studies using optical imaging have shown that enantiomerically pure DPPC molecules form periodical homochiral domains with close packing. However, it is unclear whether the chirality of these domains is stable or dynamic. Recently, we investigated the chirality of l-DPPC Langmuir monolayers using second-harmonic-generation linear dichroism (SHG-LD). The change in the degree of chiral excess (DCE) and its sign with time indicated that the chirality transformed from homochiral to heterochiral domains, with an associated change in handedness. Here we propose that hydrolysis of l-DPPC is responsible for the formation of the opposite chiral state. On the basis of quantum chemistry calculations and effective pair potential (EPP) theory, we give a molecular explanation for this transformation. These results provide an insight into the lipid monolayers that the chiral state of domains composed of chiral lipids is dynamic.

Interpretation and use of glints from an electrospinning jet of polymer solutions

Optical observations of jets provide information useful for control of electrospinning of polymer solutions. Combinations of videography, stereography, and methods for illumination of the multiple coils of an electrospinning jet path, that depend on bright glints of reflected light from the jet, recorded quantitative information about the location, vector velocity, and rotation of selected segments of the jet. New bending coils were observed to form at rates of 200–1560 turns per second. This bending frequency decreased as the capillary number of the solutions increased. The polarization of light, in glints reflected at Brewster's angle, allows measurement of the index of refraction of the fluid jet, in flight. Asymmetric illumination of an electrospinning jet made both the handedness and changes in handedness of the electrical bending coils apparent to visual observation and in 2-dimensional images. Evidence was found, in the form of polarized ribbon-like glint traces, for the occurrence of undulations on the surface of some jets.

Chopstick surgery: a novel technique enables use of the Da Vinci Robot to perform single-incision laparoscopic surgery

Single-incision laparoscopic surgery (SILS) is limited by the coaxial arrangement of the instruments. A surgical robot with "wristed" instruments could overcome this limitation but the "arms" collide when working coaxially. This video demonstrates a new technique of "chopstick surgery," which enables use of the robotic arms through a single incision without collision. Experiments were conducted utilizing the da Vinci S® robot (Sunnyvale, CA) in a porcine model with three laparoscopic ports (12 mm, 2-5 mm) introduced through a single "incision." Pilot work conducted while performing Fundamentals of Laparoscopic Surgery (FLS) tasks determined the optimal setup for SILS to be a triangular port arrangement with 2-cm trocar distance and remote center at the abdominal wall. Using this setup, an experienced robotic surgeon performed a cholecystectomy and nephrectomy in a porcine model utilizing the "chopstick" technique. The chopstick arrangement crosses the instruments at the abdominal wall so that the right instrument is on the left side of the target and the left instrument on the right. This arrangement prevents collision of the external robotic arms. To correct for the change in handedness, the robotic console is instructed to drive the "left" instrument with the right hand effector and the "right" instrument with the left. Both procedures were satisfactorily completed with no external collision of the robotic arms, in acceptable times and with no technical complications. This is consistent with results obtained in the box trainer where the chopstick configuration enabled significantly improved times in all tasks and decreased number of errors and eliminated instrument collisions. Chopstick surgery significantly enhances the functionality of the surgical robot when working through a small single incision. This technique will enable surgeons to utilize the robot for SILS and possibly for intraluminal or transluminal surgery.

Influence of temperature and terminal chain length on helical pitch in homologue series nH6Bi

The homologous series of three ring chiral esters with terminal chains, one 1-methylheptyl group and, one alkanoyloxyhexyloxy group, were studied. Compounds of these series are liquid crystals with smectic phases, that is, SmA, SmC* (ferroelectric phase) and SmC*A (antiferroelectric phase). The helical pitch was measured by a spectrophotometric method of selectively reflected light. It was found that the helical pitch increases and then decreases with temperature in the SmC*A phase for most homologues and in the SmC* phase for one homologue. The temperature characteristics of the helical pitch are related to the change in handedness of the helix.