The use of the Körperkoordinationstest für Kinder in the talent pathway in youth athletes: A systematic review.

OBJECTIVES: Identifying talented athletes from an early age to accelerate their development requires the investment of substantial resources. Due to the need for multifactorial approaches to talent identification, motor competence assessments are increasingly prevalent in contemporary testing batteries. Therefore, the aim of this review was to evaluate the literature on the use of a product-oriented motor competence assessment tool, the Körperkoordinationstest für Kinder (KTK) in the talent pathway and determine whether it is warranted in such programs. METHODS: Three electronic databases (i.e. PubMed, SPORTDiscus and Web of Science) were searched for studies that used at least one component of the KTK to assess motor competence for talent detection, identification, development and selection in athletic populations. A total of 21 articles were included in the review, of which seven used the full version of the KTK and 14 used modified versions or individual components of the battery. The quality of included studies was assessed using a modified version of the Joanna Brigg's Institute Critical Appraisal Checklist. RESULTS: The analysed literature suggests that the KTK can successfully distinguish between athletes of different competition levels and across different sporting domains, however, findings should be interpreted with caution due to the cross-sectional nature of the studies. Furthermore, the moving sideways subtest displayed the greatest discriminative power for athletes of different competition levels. Motor competence was not affected by maturation and did not differ between genders or playing positions. CONCLUSIONS: Collectively, these findings suggest that the KTK is a useful motor competence assessment in the talent pathway.

Stabilities and isomeric equilibria in solutions of monomeric metal-ion complexes of guanosine 5'-triphosphate (GTP4-) and inosine 5'-triphosphate (ITP4-) in comparison with those of adenosine 5'-triphosphate (ATP4-).

Under experimental conditions in which the self-association of the purine-nucleoside 5'-triphosphates (PuNTPs) GTP and ITP is negligible, potentiometric pH titrations were carried out to determine the stabilities of the M(H;PuNTP) and M(PuNTP)2-complexes where M2+ = Mg2+, Ca2+, Sr2+. Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, or Cd2+ (I = 0.1 M, 25 degrees C). The stabilities of all M(GTP)2- and M(ITP)2- complexes are significantly larger than those of the corresponding complexes formed with pyrimidine-nucleoside 5'-triphosphates (PyNTPs), which had been determined previously under the same conditions. This increased complex stability is attributed, in agreement with previous 1H MNR shift studies, to the formation of macrochelates of the phosphate-coordinated metal ions with N7 of the purine residues. A similar enhanced stability (despite relatively large error limits) was observed for the M(H;PuNTP) complexes, in which H+ is bound to the terminal y-phosphate group, relative to the stability of the M(H;PyNTP)- species. The percentage of the macrochelated isomers in the M(GTP)2- and M(ITP)2- systems was quantified by employing the difference log KMM(PuNTP)-log KMM(PyNTP); the lowest and highest formation degrees of the macrochelates were observed for Mg(ITP)2- and Cu(GTP)2- with 17 +/- 11% and 97 +/- 1%, respectively. From previous studies of M(ATP)2- complexes, it is known that innersphere and outersphere macrochelates may form; that is, in the latter case a water molecule is between N7 and the phosphate-coordinated M2+. Similar conclusions are reached now by comparisons with earlier 1H MNR shift measurements, that is, that Mg(GTP)2- (21 +/- 11%), for example, exists largely in the form of an outersphere macrochelate and Zn(GTP)2- (68 +/- 4%) as an innersphere one. Generally, the overall percentage of macrochelate falls off for a given metal ion in the order M(GTP)2- > M(ITP)2- > M(ATP)2-; this is in accord with the decreasing basicity of N7 and the steric inhibition of the (C6)NH2 group in the adenine residue. Furthermore, although the absolute stability constants of the previously studied M(GMP), M(IMP), and M(AMP) complexes differ by about two to three log units from the present M(PuNTP)2- results, the formation degrees of the macrochelates are astonishingly similar for the two series of nucleotides for a given metal ion and purine-nucleobase residue. The conclusion that N7 of the guanine residue is an especially favored binding site for metal ions is also in accord with observations made for nucleic acids.

Residue analytical methods for monocrotophos.

This paper summarizes and reviews a variety of methods that have been and are being used for the determination of residues of monocrotophos. Of the different techniques, gas-liquid chromatography was recommended as the technique of choice because it is sensitive as well as selective. The other techniques reviewed may still be useful in cases where gas chromatography is not available. The recommended methods were described in detail to allow their direct use by experienced residue analysts. Some multiresidue methods that include monocrotophos and may be used for surveillance purposes were briefly discussed.

Comparison of the self-association properties of the 5'-triphosphates of inosine (ITP), guanosine (GTP), and adenosine (ATP). Further evidence for ionic interactions in the highly stable dimeric [H2(ATP)]2(4-) stack.

The concentration dependence of the chemical shifts for the hydrogens H-2, H-8 and H-1' of ITP and for H-8 and H-1' of GTP has been measured in D2O at 25 degrees C under several degrees of protonation in the pD range 1.2-8.4. For reasons of comparison, inosine and guanosine have been included in the study The results are consistent with the isodesmic model of indefinite noncooperative stacking. The association constants for the nucleosides (Ns) inosine and guanosine decrease with increasing protonation: Ns greater than D(Ns)+/Ns in a 1:1 ratio greater than D(Ns)+. In contrast, a maximum is observed with ITP and GTP; the stacking tendency of GTP following the series: GTP4- less than or equal to D(GTP)3- (K approximately 0.7 M-1) less than D(GTP)3-/D2(GTP)2- in a 1:1 ratio (K approximately 2.9 M-1) greater than D2(GTP)2- greater than D3(GTP)- (K approximately 1.5 M-1). The order of the series with ITP corresponds to that with GTP, but the association constants are slightly smaller. At the maximum of the self-association tendency the triphosphate residue has only a minor influence; this follows from the fact that the association constants for the 1:1 ratios of Ino/D(Ino)+ and D(ITP)3-/D2(ITP)2- are identical within experimental error; this holds also for Guo/D(Guo)+ and D(GTP)3-/D2(GTP)2-; in all these pairs the K-7 site is 50% protonated. Comparison of the association constant for the deprotonated species shows that here charge effects, i.e. repulsion between the negatively charged triphosphate chains, are important: Ino (K approximately 3.3 M-1) greater than ITP4- (K approximately 0.4 M-1) and Guo (K approximately 8 M-1) greater than GTP4- (K approximately 0.8 M-1). In addition the series holds: Ado (K approximately 15 M-1) greater than Guo greater than Ino. However, most important is the comparison of the ITP and GTP series with previous data for ATP: ATP4- (K approximately 1.3 M-1) less than D(ATP)3- (2.1 M-1) less than 1:1 ratio of D(ATP)3-/D2(ATP)2- (6 M-1) much less than D2(ATP)2- (approximately 200 M-1) much greater than D3(ATP)- (K less than or equal to 17 M-1).(ABSTRACT TRUNCATED AT 400 WORDS)

Metal-ion-governed molecular recognition: extent of intramolecular stack formation in mixed-ligand--copper(II) complexes containing a heteroaromatic N base and an adenosine monophosphate (2'AMP, 3'AMP, or 5'AMP). A structuring effect of the metal-ion bridge.

Stability constants of mixed-ligand Cu(Arm)(AMP) complexes [where Arm = 2,2'-bipyridyl (Bpy) or 1,10-phenanthroline (Phen) and AMP2- = 2'AMP2-, 3'AMP2- or 5'AMP2-] were determined by potentiometric pH titrations in aqueous solution at I = 0.1 M (NaNO3) and 25 degrees C. The ternary Cu(Arm)(AMP) complexes are more stable than corresponding Cu(Arm)(R-MP) complexes, where R-MP2- represents a phosphate monoester with a group R that is unable to participate in any kind of interaction within the complexes as, for example, D-ribose 5'-monophosphate. This increased stability is attributed, in agreement with previous results, to intramolecular stack formation in the Cu(Arm)(AMP) complexes between the purine residue of the AMPs and the aromatic rings of Bpy or Phen. Based on correlation lines (previously obtained from log K versus pKa plots) for Cu(Arm)(R-MP) complexes without a ligand-ligand interaction, a quantitative evaluation was carried out. The degree of formation of the species with the intramolecular stacks increases for the Cu(Arm)(AMP) complexes in the series: 3'AMP2- less than 5'AMP2- less than 2'AMP2-; e.g. in Cu(Bpy)(3'AMP) the stack reaches a formation degree of 45 +/- 11% and in Cu(Bpy)(2'AMP) one of 96.1 +/- 0.7% is obtained. It must be emphasized that these differences are due to the different steric orientations of the bridging metal ion, which result from the varying position of the phosphate group on the ribose ring. As shown by 1H-NMR shift measurements, there is no significant effect of the position of the phosphate group on the stability of the binary (Phen)(AMP)2- adducts (K approximately 36 M-1 in D2O); such an effect is seen only if a metal-ion bridge is formed between the moieties forming the stack, i.e. metal-ion coordination imposes individual properties on the AMPs. By also taking into account some recent results on other nucleoside 5'-monophosphate complexes, the following trend for an increasing stacking tendency of the nucleic base moieties can be established: uracil approximately less than cytosine approximately less than thymine much less than adenine less than 7-deazaadenine. Some additional conclusions of general importance are given and the relevance of the results with regard to bio-systems is indicated.

Rh(DIP)3(3+): a shape-selective metal complex which targets cruciforms.

The coordination complex tris(4,7-diphenylphenanthroline)rhodium(III), Rh(DIP)3(3+), binds to and, upon photoactivation, cleaves both DNA strands near the base of a DNA cruciform. Sites of photoinduced double-stranded DNA cleavage by the rhodium complex map to regions containing cruciforms on closed circular pBR322, pColE1 and phi X174 (replicative form) DNAs. Neither cleavage nor binding by the metal complex, assayed using S1 nuclease, is found on the linear plasmid which lacks the extruded cruciform. High resolution mapping experiments reveal that Rh(DIP)3(3+) cleaves at a specific AT-rich site neighboring the stem of the minor cruciform on pBR322. The primary site of cleavage is found at position 3238 on the 3'-strand and 3250 on the 5'-strand and is remarkably specific. The pattern of cleavage, to one side only of the cruciform stem, indicates an asymmetry in the cruciform structure recognized by the complex. These results suggest that Rh(DIP)3(3+) may provide a useful reagent to probe cruciform sites. In addition, the high degree of specificity found in targeting the cruciform structure with this simple metal complex underscores the utility of shape-selection for the recognition of specific sites on a DNA strand.

Influence of the protonation degree on the self-association properties of adenosine 5'-triphosphate (ATP).

The concentration dependence of the chemical shifts for the protons H-2, H-8 and H-1' of ATP has been measured in D2O at 27 degrees C under several degrees of protonation in the pD range from 1.5 to 8.4. The results at pD greater than 4.5 are consistent with the isodesmic model of indefinite noncooperative stacking, while those at pD less than 4.5 indicate a preference for the formation of dimeric stacks. The stacking tendency follows the series, ATP4- (K = 1.3 M-1) less than D(ATP)3- (2.1 M-1) less than 1:1 ratio of D(ATP)3-/D2(ATP)-2- (6.0 M-1) much less than D2(ATP)2- (approximately 200 M-1) much greater than D3(ATP)- (K approximately less than 17 M-1) (for reasons of comparison all constants are expressed in the isodesmic model). These results are compared with previous data for adenosine [Ado (K = 15 M-1) greater than 1:1 ratio of Ado/D(Ado)+ (6.0 M-1) greater than D(Ado)+ (0.9 M-1)] and AMP [AMP2- (K = 2.1 M-1) less than D(AMP)- (3.4 M-1) less than 1:1 ratio of D(AMP)-/D2(AMP) +/- (5.6 M-1) greater than D2(AMP) +/- (approximately equal to 2 M-1) greater than D3(AMP)+ (K less than or equal to 1 M-1)] to facilitate the interpretation of the results for the ATP systems. Stack formation of H2(ATP)2- is clearly favored by additional ionic interactions; this is confirmed by measuring via potentiometric pH titrations the acidity constants of H2(ATP)2- in solutions containing different concentrations of ATP. It is suggested that in the [H2(ATP)]4-(2) dimer intermolecular ion pairs (and hydrogen bonds) are formed between the H+(N-1) site of one H2(ATP)2- and the gamma-P(OH)(O)-2 group of the other; in this way (a) the stack is further stabilized, and (b) the positive charges at the adenine residues are compensated (otherwise repulsion would occur as is evident from the adenosine systems). A detailed structure for the [H2(ATP)4-(2) dimer is proposed and some implications of the described stacking properties of ATP for biological systems are indicated.

Self-association of adenosine 5'-monophosphate (5'-AMP) as a function of pH and in comparison with adenosine, 2'-AMP and 3'-AMP.

The concentration dependence of the chemical shifts for protons H-2, H-8, and H-1' of adenosine (Ado), 2'-AMP, 3'-AMP and 5'-AMP was measured in D2O at 27 degrees C under several degrees of protonation. All results are consistent with the isodesmic model of indefinite noncooperative stacking. The association constants for Ado decrease with increasing protonation: Ado (K = 15 M-1) greater than D(Ado)+/Ado (6.0 M-1) greater than D(Ado)+ (0.9 M-1). In contrast, a maximum is observed with 5'-AMP: 5'-AMP2- (K = 2.1 M-1) less than D(5'-AMP)- (3.4 M-1) less than D2(5'-AMP) +/- /D(5'-AMP)- (5.6 M-1) greater than D2(5'-AMP) +/- (approximately 2 M-1) greater than D3(5'-AMP)+ (less than or equal to 1 M-1). Self-stacking is most pronounced here if 50% of the adenine residues are protonated at N-1; complete base protonation reduces the stacking tendency drastically. Comparing the self-association of 2'-, 3'- and 5'-AMP shows that there is no influence of the phosphate-group position in the 2-fold negatively charged species, i.e., K congruent to 2 M-1 for all three AMP2- species. More importantly, there is also no significant influence observed if the stacking tendency of the three D2(AMP) +/- /D(AMP)-1:1 mixtures is compared (K congruent to 6-7 M-1); moreover, the measured association constants are within experimental error identical with the constant determined for D(Ado)+/Ado (K = 6.0 M-1). This indicates that any coulombic contribution between the -PO3(H)- group and the H+ (N-1) unit of the adenine residue to the stability of the mentioned stacks in D2O is small. However, experiments in 50% (v/v) dioxane-D8/D2O with the D2(5'-AMP) +/- /D(5'-AMP)- 1:1 system reveal, despite its low solubility, that coulombic interactions contribute to the self-association in an environment with a reduced polarity (compared to that of water). The implications of these observations for biological systems are briefly indicated.

Self-association and protonation of adenosine 5'-monophosphate in comparison with its 2'- and 3'-analogues and tubercidin 5'-monophosphate (7-deaza-AMP).

The concentration dependence of the chemical shifts of the protons H-2, H-8 and H-1' for 2'-, 3'- and 5'-AMP2- and of the protons H-2, H-7, H-8 and H-1' for tubercidin 5'-monophosphate (= 7-deaza-AMP2-; TuMP2-) has been measured in D2O at 27 degrees C to elucidate the self-association of the nucleoside monophosphates (NMPs). The results are consistent with the isodesmic model of indefinite non-cooperative stacking; the association constants for all four NMPs are very similar: K approximately 2 M-1. These 1H-NMR measurements and those on the dependence of the chemical shifts on the pD of the solutions indicate that the NMP2- species exist predominately in the anti conformation. Comparison of the shift data for 5'-TuMP and 5'-AMP shows that no hydrogen bonding between N-7 and -PO3H- occurs; hence, the previously observed and confirmed 'wrongway' chemical shift [Martin, R. B. (1985) Acc. Chem. Res 18, 32] connected with the deprotonation of the -PO3H- group most probably results from the anisotropic properties of the phosphate group which is in the anti conformation close to N-7. From the dependence between the chemical shift and the pD of the solutions the acidity constants were calculated for the four protonated NMPs, and for adenosine and D-ribose 5'-monophosphate. The measurements also allow an estimation of the first acidity constant of H3(5'-AMP)+ (pKDD3(AMP) = 0.9 and pKHH3(AMP) = 0.4). The values for pKHH2(NMP) and pKHH(NMP) were also determined from potentiometric pH titrations in aqueous solution (I = 0.1 M, NaNO3; 25 degrees C). The agreement of the results obtained by the two methods is excellent. The position of the phosphate group at the ribose moiety and the presence of N-7 in the base moiety influence somewhat the acid-base properties of the mentioned NMPs. Measurements with 5'-AMP in 50% (v/v) aqueous dioxane show that lowering of the solvent polarity facilitates removal of the proton from the H+(N-1) site while the -PO2-3 group becomes more basic; this increases the pH range in which the monoprotonated H(5'-AMP)- species is stable and which is now also extended into the physiological pH region. Some consequences of this observation for biological systems are indicated.

An estimation of the equivalent solution dielectric constant in the active-site cavity of metalloenzymes. Dependence of carboxylate-metal-ion complex stabilities on the polarity of mixed aqueous/organic solvents.

The stability constants of the 1:1 complexes between Cu2+ and Zn2+ with formate, acetate and several phenylalkanecarboxylates, i.e. C6H5-(CH2)n-COO- with n = 0 to 5, are summarized for water, 50% aqueous ethanol and 50% aqueous dioxane (I = 0.1 M; 25 degrees C): Complex stability depends upon carboxylate group basicity. The influence of varying amounts of ethanol or dioxane (up to 90%) on the stability of the Cu2+ and Zn2+ (M2+) complexes with formate and acetate (CA) was measured by potentiometric pH titrations. The values for pKHH(CA) and log KMM(CA) increase, as expected, with increasing amounts of the organic solvents, i.e. with decreasing solvent polarity. The changes in the equilibrium constants are also evaluated with regard to the mole fractions of the organic solvents and the corresponding dielectric constants. These results may be used to estimate for low dielectric cavities in proteins the equivalent solution dielectric constant on the basis of enhanced carboxylate basicity or metal ion binding capability (method 1). Furthermore, the measured stability constants are used for comparisons of the coordination tendency of carboxylate ligands towards zinc(II)-metalloenzymes (method 2); in this way the equivalent solution dielectric constants in the active-site cavities of bovine carbonic anhydrase and carboxypeptidase A are estimated: the values are of the order of 35 and 70, respectively. This method seems to be generally applicable to metalloproteins.

Metal ion/buffer interactions. Stability of binary and ternary complexes containing 2-amino-2(hydroxymethyl)-1,3-propanediol (Tris) and adenosine 5'-triphosphate (ATP).

The interaction of 2-amino-2(hydroxymethyl)-1,3-propanediol (Tris) with the metal ions (M2+) Mg2+, Ca2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, and Pb2+ was studied by potentiometry and spectrophotometry in aqueous solution (I = 0.1 or 1.0 M, KNO3, 25 degrees C). Stability constants of the M(Tris)2+ complexes were determined; those constants which were measured by both methods agreed well. Ternary complexes containing ATP4- as a second ligand were also investigated and it is shown that in the presence of Tris, mixed-ligand complexes of the type M(ATP)(Tris)2- are formed. The values for delta log KM, where delta log KM = log KM(ATP)M(ATP)Tris--log KMM(Tris), are all negative, thus indicating that the interaction of Tris with M(ATP)2- is somewhat less pronounced than with M2+. However, it should be noted that even in mixed-ligand systems complex formation with Tris may still be considerable, hence great reservations should be exercised in employing Tris as a buffer in systems which also contain metal ions. Distributions of the complex species in dependence on pH are shown for several systems, and the structures of the binary M(Tris)2- and the ternary M(ATP)(Tris)2- complexes are discussed. The participation of a Tris-hydroxo group in complex formation is, at least for the M(Tris)2- species, quite evident.