Combinatory Operations Research Articles

Good Outcomes of Combined Femoral Derotation Osteotomy and Medial Retinaculum Plasty in Patients with Recurrent Patellar Dislocation.

ObjectivesTo report the clinical outcomes of combined femoral derotation osteotomy and medial retinaculum plasty for recurrent patellar dislocation in patients with excessive femoral anteversion.MethodsFrom January 2015 to March 2018, 20 knees in 20 patients (18 female, 2 male) with a mean age of 21 ± 4.2 years (range, 16 to 28 years) were retrospectively reviewed. All patients had undergone femoral derotation osteotomy and medial retinaculum plasty for recurrent patellar dislocation and excessive femoral anteversion angle (FAA > 25°). CT and X‐rays were used to assess the correction of the femoral anteversion angle, the tibia tuberosity‐trochlear groove (TT‐TG) distance, patellar tilt, and the congruence angle following the combinatory operations. Subjective scores, such as Kujala, International Knee Documentation Committee (IKDC), Tegner, and visual analogue scale (VAS) scores, were used to evaluate knee function preoperatively and postoperatively.ResultsNo recurrence of patellar dislocation occurred in these patients during an average of 18 months (range, 12 to 23 months) of follow‐up. The mean of the FAA was corrected to 15.80° ± 3.58° postoperatively compared with 31.42° ± 4.95° preoperatively (P < 0.001). The TT‐TG distance was decreased from 22.17 ± 5.28 mm before surgery to 19.42 ± 4.57 mm after surgery (P = 0.03). The patellar tilt and congruence angle were improved from 30.43° ± 5.30°, 43.30° ± 11.04° to 15.80° ± 3.94°, 16.64° ± 9.98°, respectively (P < 0.001). The Kujala score was improved from 72.4 ± 19.90 before the surgery to 88.2 ± 12.25 after the surgery (P < 0.001). The IKDC score was improved from 70.56 ± 21.44 to 90.78 ± 14.32, and the VAS score was decreased from 4.23 ± 2.11 preoperatively to 1.27 ± 1.08 postoperatively (P < 0.001). No significant difference in Tegner score (5.46 ± 2.49 vs 5.79 ± 1.44) was found before and after the surgery (P = 0.2). Patients younger than 20 years old had lower Kujala (83.46 ± 14.56 vs. 90.84 ± 7.74, P = 0.02) and IKDC (83.49 ± 17.35 vs 92.46 ± 9.28, P = 0.04) scores than those older than 20 years.ConclusionGood knee function, pain relief, and improved patellofemoral congruence were achieved with the combined femoral derotation osteotomy and medial retinaculum plasty. The combined operations serve as an ideal treatment for recurrent patellar dislocation and address the primary risk factors.

Building words and phrases in the left temporal lobe

A central part of knowing a language is the ability to combine basic linguistic units to form complex representations. While our neurobiological understanding of how words combine into larger structures has significantly advanced in recent years, the combinatory operations that build words themselves remain unknown. Are complex words such as tombstone and starlet built with the same mechanisms that construct phrases from words, such as grey stone or bright star? Here we addressed this with two magnetoencephalography (MEG) experiments, which simultaneously varied demands associated with phrasal composition, and the processing of morphological complexity in compound and suffixed nouns. Replicating previous findings, we show that portions of the left anterior temporal lobe (LATL) are engaged in the combination of modifiers and monomorphemic nouns in phrases (e.g., brown rabbit). As regards compounding, we show that semantically transparent compounds (e.g., tombstone) also engage left anterior temporal cortex, though the spatiotemporal details of this effect differed from phrasal composition. Further, when a phrase was constructed from a modifier and a transparent compound (e.g., granite tombstone), the typical LATL phrasal composition response appeared at a delayed latency, which follows if an initial within-word operation (tomb + stone) must take place before the combination of the compound with the preceding modifier (granite + tombstone). In contrast to compounding, suffixation (i.e., star + let) did not engage the LATL in any consistent way, suggesting a distinct processing route. Finally, our results suggest an intriguing generalization that morpho-orthographic complexity that does not recruit the LATL may block the engagement of the LATL in subsequent phrase building. In sum, our findings offer a detailed spatiotemporal characterization of the lowest level combinatory operations that ultimately feed the composition of full sentences.

The priming of basic combinatory responses in MEG

Priming has been a powerful tool for the study of human memory and especially the memory representations relevant for language. However, although it is well established that lexical access can be primed, we do not know exactly what types of computations can be primed above the word level. This work took a neurobiological approach and assessed the ways in which the complex representation of a minimal combinatory phrase, such as red boat, can be primed, as evidenced by the spatiotemporal profiles of magnetoencephalography (MEG) signals. Specifically, we built upon recent progress on the neural signatures of phrasal composition and tested whether the brain activities implicated for the basic combination of two words could be primed. In two experiments, MEG was recorded during a picture naming task where the prime trials were designed to replicate previously reported combinatory effects and the target trials to test whether those combinatory effects could be primed. The manipulation of the primes was successful in eliciting larger activity for adjective-noun combinations than single nouns in left anterior temporal and ventromedial prefrontal cortices, replicating prior MEG studies on parallel contrasts. Priming of similarly timed activity was observed during target trials in anterior temporal cortex, but only when the prime and target shared an adjective. No priming in temporal cortex was observed for single word repetition and two control tasks showed that the priming effect was not elicited if the prime pictures were simply viewed but not named. In sum, this work provides evidence that very basic combinatory operations can be primed, with the necessity for some lexical overlap between prime and target suggesting combinatory conceptual, as opposed to syntactic processing. Both our combinatory and priming effects were early, onsetting between 100 and 150ms after picture onset and thus are likely to reflect the very earliest planning stages of a combinatory message. Thus our findings suggest that at the earliest stages of combinatory planning in production, a combinatory memory representation is formed that affects the planning of a relevantly similar combination on a subsequent trial.

The role of the IFG and pSTS in syntactic prediction: Evidence from a parametric study of hierarchical structure in fMRI

Sentences encode hierarchical structural relations among words. Several neuroimaging experiments aiming to localize combinatory operations responsible for creating this structure during sentence comprehension have contrasted short, simple phrases and sentences to unstructured controls. Some of these experiments have revealed activation in the left inferior frontal gyrus (IFG) and posterior superior temporal sulcus (pSTS), associating these regions with basic syntactic combination. However, the wide variability of these effects across studies raises questions about this interpretation. In an fMRI experiment, we provide support for an alternative hypothesis: these regions underlie top-down syntactic predictions that facilitate sentence processing but are not necessary for building syntactic structure. We presented stimuli with three levels of structure: unstructured lists, two-word phrases, and simple, short sentences; and two levels of content: natural stimuli with real words and stimuli with open-class items replaced with pseudowords (jabberwocky). While both the phrase and sentence conditions engaged syntactic combination, our experiment only encouraged syntactic prediction in the sentence condition. We found increased activity for both natural and jabberwocky sentences in the left IFG (pars triangularis and pars orbitalis) and pSTS relative to unstructured word lists and two-word phrases, but we did not find any such effects for two-word phrases relative to unstructured word lists in these areas. Our results are most consistent with the hypothesis that increased activity in IFG and pSTS for basic contrasts of structure reflects syntactic prediction. The pars opercularis of the IFG showed a response profile consistent with verbal working memory. We found incremental effects of structure in the anterior temporal lobe (ATL), and increased activation only for sentences in the angular gyrus (AG)/temporal–parietal junction (TPJ) – both regions showed these effects for stimuli with all real words. These findings support a role for the ATL in semantic combination and the AG/TPJ in thematic processing.

Adjective conjunction as a window into the LATL’s contribution to conceptual combination

Though a large literature implicates the left anterior temporal lobe (LATL) for combinatory operations, recent MEG studies have suggested that it is specifically involved in the composition of complex concepts, rather than syntactic or semantic composition in a more general sense. To further specify the computational contribution of the LATL, we tested whether LATL effects as observed in MEG require a situation in which features combine to form a single coherent entity representation or whether the relevant computation simply requires the attribution of features to a set but not necessarily to the same members of the set. Under the former hypothesis, the LATL would be sensitive to the number of features added to the representation of a single entity whereas under the latter account, LATL activity would reflect the total number of features integrated across different members of a set. To test this, we employed conjunctions of two adjectives whose lexical semantics were varied such that they either allowed or disallowed the attribution of their denoted properties to the same members of a set, i.e., the properties were either compatible or incompatible. The compatible properties resulted in so-called intersective and the incompatible in so-called collective readings. Our results show that the LATL tracks the number of features attributed to an individual as opposed to the number of features attributed to a set. Interestingly, the reverse pattern was found in the right ATL, demonstrating that although this region often shows parallel effects to the LATL, its functional contribution is clearly distinct.

Composition of complex numbers: Delineating the computational role of the left anterior temporal lobe

What is the neurobiological basis of our ability to create complex messages with language? Results from multiple methodologies have converged on a set of brain regions as relevant for this general process, but the computational details of these areas remain to be characterized. The left anterior temporal lobe (LATL) has been a consistent node within this network, with results suggesting that although it rather systematically shows increased activation for semantically complex structured stimuli, this effect does not extend to number phrases such as ‘three books.’ In the present work we used magnetoencephalography to investigate whether numbers in general are an invalid input to the combinatory operations housed in the LATL or whether the lack of LATL engagement for stimuli such as ‘three books’ is due to the quantificational nature of such phrases. As a relevant test case, we employed complex number terms such as ‘twenty-three’, where one number term is not a quantifier of the other but rather, the two terms form a type of complex concept. In a number naming paradigm, participants viewed rows of numbers and depending on task instruction, named them as complex number terms (‘twenty-three’), numerical quantifications (‘two threes’), adjectival modifications (‘blue threes’) or non-combinatory lists (e.g., ‘two, three’). While quantificational phrases failed to engage the LATL as compared to non-combinatory controls, both complex number terms and adjectival modifications elicited a reliable activity increase in the LATL. Our results show that while the LATL does not participate in the enumeration of tokens within a set, exemplified by the quantificational phrases, it does support conceptual combination, including the composition of complex number concepts.

Либерализм и регулирование финансового рынка

Reagan's financial sector deregulation became a starting point for the financial engineering, derivatives, combinatory financial operations industry. Due to it hedge funds developed, and a range of risk financial transactions expanded among the banks that found both new forms of financial risk hedging and new sources of income: arbitrage and hedging, credit default swaps, operations with "second-rate” credits. It was them that exploded the market in 2007–2008. The reaction of states realized in a string of regulation initiatives, including creation of supranational coordination bodies (in particular, Financial Stability Board); reformatting of mega regulators and on their base – the shaping of state prudential supervision and financial services consumer rights protection bodies with different tasks; restrictions on hedge funds activities; toughening of derivative instruments regulation and implementing of a central counterparty institute on derivatives market.

Plans, Affordances, And Combinatory Grammar

The idea that natural language grammar and planned action are relatedsystems has been implicit in psychological theory for more than acentury. However, formal theories in the two domains have tendedto look very different. This article argues that both faculties sharethe formal character of applicative systems based on operationscorresponding to the same two combinatory operations, namely functional composition and type-raising. Viewing them in thisway suggests simpler and more cognitively plausible accounts of bothsystems, and suggests that the language faculty evolved in the speciesand develops in children by a rather direct adaptation of a moreprimitive apparatus for planning purposive action in the world bycomposing affordances of objects or tools. Theknowledge representation that underlies such planning is alsoreflected in the natural language semantics of tense, mood, andaspect, which the paper begins by arguing provides the key tounderstanding both systems.

Dimensions and Patterns in Decision-making Models and the Controlled/Automatic Distinction in Human Information Processing

Dimensional and compound pattern decision models are examined, and their respective compatibility with analytical and holistic approaches is indicated. It is shown that dimensional models depict strategies that depend on analysis and evaluation of the dimensions of choice alternatives, followed by either using complex combinatory and comparison operations, or some short-cut rules that rely on processing partial information. Compound pattern models, in contrast, underscore processes of matching whole patterns. It is argued here that the type of processes emphasised by models that assume dimensional analysis can be classified as directed/attentional processes, whereas matching of whole patterns depends more on automatic processes. Current approaches to the automatic/controlled distinction in various domains are then presented, and their relevance to decision-making models is discussed.

Structural complexity and the time course of grammatical development

One traditional view of the time course of language acquisition holds that a child's difficulties in learning her language are due to general processing, memory or conceptual limitations. As the child's cognitive capacities expand, so do her abilities to use her already-acquired grammar or to recognize additional properties of her soon-to-be native language. Recent work in the study of child language, however, has discovered the existence of a number of characteristic stages, transitions between which are best described in the terms of linguistic theory proper. These stages are surprising under a view of language acquisition according to which developmental delay derives from general cognitive limitations, which cannot characterize difficulties explicable only in language-specific terms. At the same time, current linguistic theories so severely restrict the variation among possible human grammars that there remains little reason why there should be any learning problem at all or characteristic developmental stages. In this paper, I propose that these two views can be reconciled. I show that children's difficulties with a wide range of syntactic constructions, which are indeed best defined in linguistic terms, should nonetheless be derived from limitations on the child's ability to deal with processing load and formal representational complexity. I suggest however that this can be done only in the context of a particular view of syntactic representation, one which is articulated in the terms of the formal system of tree adjoining grammar (TAG). I demonstrate how precisely those difficulties that children experience in the acquisition of relative clauses, adjectival modification, control constructions, raising, wh-questions and the obligatoriness of finite inflection can be traced to the complexity associated with one of the TAG combinatory operations, adjoining. This proposal relates this apparently disparate set of constructions in a novel way and provides us with a new type of explanation for the time course of syntactic development in terms of the complexity of formal grammatical devices.

Hemispheric differences in mathematical problem solving: combinatory operations.

Subjects with right and left frontal and non-frontal lesions, and a control group were asked to solve mathematical problems of simple combinatory operations. Subjects with lesions in the left frontal area were found to be significantly inferior.