Van Schijndel Research Articles

Supporting Early Scientific Thinking Through Curiosity.

Curiosity and curiosity-driven questioning are important for developing scientific thinking and more general interest and motivation to pursue scientific questions. Curiosity has been operationalized as preference for uncertainty (Jirout and Klahr, 2012), and engaging in inquiry-an essential part of scientific reasoning-generates high levels of uncertainty (Metz, 2004; van Schijndel et al., 2018). This perspective piece begins by discussing mechanisms through which curiosity can support learning and motivation in science, including motivating information-seeking behaviors, gathering information in response to curiosity, and promoting deeper understanding through connection-making related to addressing information gaps. In the second part of the article, a recent theory of how to promote curiosity in schools is discussed in relation to early childhood science reasoning. Finally, potential directions for research on the development of curiosity and curiosity-driven inquiry in young children are discussed. Although quite a bit is known about the development of children’s question asking specifically, and there are convincing arguments for developing scientific curiosity to promote science reasoning skills, there are many important areas for future research to address how to effectively use curiosity to support science learning.

Comment on “Evidence for Mesoproterozoic collision, deep burial and rapid exhumation of garbenschiefer in the Namaqua Front, South Africa” by Valby Van Schijndel, David H. Cornell, Robert Anczkiewicz, Anders Scherstén, Geoscience Frontiers, Volume 11, Issue 2, Pages 511-531

Comment on “Evidence for Mesoproterozoic collision, deep burial and rapid exhumation of garbenschiefer in the Namaqua Front, South Africa” by Valby Van Schijndel, David H. Cornell, Robert Anczkiewicz, Anders Scherstén, Geoscience Frontiers, Volume 11, Issue 2, Pages 511-531

Reply to comment by S.H. Büttner on “Evidence for Mesoproterozoic collision, deep burial and rapid exhumation of garbenschiefer in the Namaqua Front, South Africa ˮ

Abstract We thank Prof. Buttner for his comments on our paper (van Schijndel et al., 2020), which allow us to clarify our work and the tectonic model we proposed for the eastern margin of the Namaqua Sector of the Namaqua Natal Metamorphic Province. The Kaaien Terrane forms a tectonic transition between the Kaapvaal Craton, Rehoboth Province, Kheis belt and the Archeachap Terrane of the Namaqua Sector and forms part of an NW-vergent foreland thrust sequence in the Namaqua Front (e.g. Cornell et al., 2006). The exact tectonic extent of the Kaaien Terrane is still unclear and it has recently been proposed to be part of the newly defined Kheis Terrane (Van Niekerk and Beukes, 2019). Buttner (2020) states that the tectonic model for the Mesoproterozoic evolution of Namaqua Sector which envisages the collision of multiple exotic terranes after the subduction of multiple oceanic basins (e.g. Miller 2012, and references therein) is outdated and newer tectonic models have been discussed in the literature in recent years. Bial et al. (2015a, 2015b, 2016) and Macey et al. (2018) propose a continental back-arc mobile belt setting to explain the high temperature and low pressure history of several terranes of the Namaqua Sector. For example, Pressure-Temperature time (P-T-t) paths describing the crustal evolution for the Kakamas Terrane by Bial et al. (2015a) suggest along-lasting high-temperature history (>650°C) at pressure not exceeding 5.5 kbar between ∼1350 Ma and

AN UNUSUAL CASE OF HERPES SIMPLEX VIRUS PNEUMONIA WITH NECROTIC AND CAVITARY CHANGES

SESSION TITLE: Global Case Report Posters SESSION TYPE: Global Case Reports PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Herpes simplex virus (HSV) pneumonia can occur in both immunocompromised and immunocompetent patients. Ground glass opacities, consolidation, and pleural effusions are observed in HSV pneumonia. Neither necrosis nor cavitation has been reported in areas of parenchymal disease. We describe a case of HSV pneumonia with unusual multiple cavitary and necrotic changes. CASE PRESENTATION: A 63-year-old woman was referred to us on January 15, 2019. She had been managed as a case of community-acquired pneumonia for 15 days at another hospital but had been progressed to respiratory failure. On January 2, chest CT scan showed peribronchial and subpleural patchy consolidation, and multiple small nodules in both lungs. She was intubated on January 4. She had a medical history of hypertension. She was newly diagnosed with diabetes at admission. Upon admission, broad spectrum antibiotics were administered but she did not improve. On January 23, chest CT showed progressive necrotic and cavitary changes in areas of consolidation and small nodules in both lungs. Bilateral pleural effusion was also increased with multiple necrotic lymph nodes. Bronchoscopy on the same day showed scattered whitish plaque-like lesions, especially on both lower lobe bronchi. Biopsy showed ulceration, necrotic inflammatory exudate, extensive squamous metaplasia and several multinucleated epithelial cells containing intranuclear inclusions, consistent with HSV or varicella-zoster virus infection. Immunohistochemical staining showed a positive reaction to HSV. Viral serology, PCR, and viral, bacterial, and fungal cultures with bronchial aspirate showed negative results. Acyclovir therapy was started on January 24. Percutaneous catheter drainage was performed for left exudative pleural effusion. The patient improved slowly; a CT scan on February 12 showed overall improvement. She was moved to the general ward after being weaned off mechanical ventilation on February 14. DISCUSSION: HSV pneumonitis cannot be diagnosed based on imaging alone; evidence of viral cytopathic effect on cytologic and/or histopathologic specimens with confirmation of HSV infection via culture, PCR, or immunohistochemical staining is required. Detection of histological hallmarks of HSV infection, such as multinucleated cells with ground glass intranuclear changes and Cowdry type A intranuclear inclusion bodies, is specific for true lower respiratory tract infections rather than a carrier state, especially in critically ill patients. In this case, we could confirm HSV pneumonia by typical endobronchial lesions, histopathologic findings, immunohistochemical staining, and overall improvement on follow-up chest CT with acyclovir therapy. CONCLUSIONS: To our knowledge, this is the first reported case of HSV pneumonia with multiple cavitary and necrotic changes in areas of consolidation and nodules. Reference #1: Chong S, Kim TS, Cho EY. Herpes simplex virus pneumonia: high-resolution CT findings. Br J Radiol 2010; 83:585–589. Reference #2: Aquino SL, Dunagan DP, Chiles C, Haponik EF. Herpes simplex virus 1 pneumonia: patterns on CT scans and conventional chest radiographs. J Comput Assist Tomogr 1998; 22(5):795-800. Reference #3: Simoons-Smit AM, Kraan EM, Beishuizen A, Strack van Schijndel AJ, Vandenbroucke-Grauls CM. Herpes simplex virus type 1 and respiratory disease in critically-ill patients: real pathogen or innocent bystander? Clin Microbiol Infect 2006; 12:1050–1059 DISCLOSURES: No relevant relationships by Cheol-Woo Kim, source=Web Response No relevant relationships by Hong Lyeol Lee, source=Web Response

Investigating locality effects and surprisal in written English syntactic choice phenomena

We investigate the extent to which syntactic choice in written English is influenced by processing considerations as predicted by Gibson’s (2000) Dependency Locality Theory (DLT) and Surprisal Theory (Hale, 2001; Levy, 2008). A long line of previous work attests that languages display a tendency for shorter dependencies, and in a previous corpus study, Temperley (2007) provided evidence that this tendency exerts a strong influence on constituent ordering choices. However, Temperley’s study included no frequency-based controls, and subsequent work on sentence comprehension with broad-coverage eye-tracking corpora found weak or negative effects of DLT-based measures when frequency effects were statistically controlled for (Demberg & Keller, 2008; van Schijndel, Nguyen, & Schuler 2013; van Schijndel & Schuler, 2013), calling into question the actual impact of dependency locality on syntactic choice phenomena. Going beyond Temperley’s work, we show that DLT integration costs are indeed a significant predictor of syntactic choice in written English even in the presence of competing frequency-based and cognitively motivated control factors, including n-gram probability and PCFG surprisal as well as embedding depth (Wu, Bachrach, Cardenas, & Schuler, 2010; Yngve, 1960). Our study also shows that the predictions of dependency length and surprisal are only moderately correlated, a finding which mirrors Dember & Keller’s (2008) results for sentence comprehension. Further, we demonstrate that the efficacy of dependency length in predicting the corpus choice increases with increasing head-dependent distances. At the same time, we find that the tendency towards dependency locality is not always observed, and with pre-verbal adjuncts in particular, non-locality cases are found more often than not. In contrast, surprisal is effective in these cases, and the embedding depth measures further increase prediction accuracy. We discuss the implications of our findings for theories of language comprehension and production, and conclude with a discussion of questions our work raises for future research.

Private damages in EU competition law and arbitration—a changing landscape

There are various obstacles within the EU Member States, which currently prevent, to a greater or lesser extent, the possibility to successfully obtain damages for harm caused by an infringement of the EU competition rules. On 26 November 2014, an EU Directive on antitrust damages actions was adopted. This sets out some minimum ground rules in order to level the playing field across the Member States with a view to making it easier to actually pursue such actions and claims successfully. On a broader level, the Directive has incorporated specific provisions to promote the effective use of consensual dispute resolution as an alternative route to enabling the victims of EU competition law infringements to obtain compensation. This paper discusses the provisions of the Directive, in terms of its potential impact on the use of arbitration to obtain private damages within the EU. It outlines and analyses the existing legislative framework in relation to the public and private enforcement of EU competition law within the EU, the possibility to arbitrate EU competition law infringements and arbitration of EU competition law in practice. It then outlines and discusses both the provisions of the Directive in relation to consensual dispute resolution and some of its most relevant and noteworthy other provisions, in particular with regard to their potential impact on the arbitration of cases involving EU competition law infringements. Finally, the paper concludes on the potential for arbitration in this area in the future and whether the Directive is likely to have much of an impact in this regard. Directive 2014/104/EU on antitrust damages actions (2014) Council Regulation (EC) 139/2004 of 20 January 2004 on the control of concentrations between undertakings (the EC Merger Regulation) (2004) Case 102/81 Nordsee v Reederei Mond , European Court of Justice (1982) Case C-88/91 Federconsorzi , European Court of Justice (1992) Cases C-430/93 and C-431/93 Van Schijndel and van Veen v Stichting Pensioenfonds voor Fysiotherapeuten , European Court of Justice (1995) Case C-126/97 Eco Swiss China Time Ltd v Benetton International NV , European Court of Justice (1999) Mitsubishi Motors Corporation v Soler Chrysler Plymouth Inc , US Supreme Court (1985)

On the Use of the Distortion-Sensitivity Approach in Examining the Role of Linguistic Abilities in Speech Understanding in Noise

Researchers have used the distortion-sensitivity approach in the psychoacoustical domain to investigate the role of auditory processing abilities in speech perception in noise (van Schijndel, Houtgast, & Festen, 2001; Goverts & Houtgast, 2010). In this study, the authors examined the potential applicability of the distortion-sensitivity approach for investigating the role of linguistic abilities in speech understanding in noise. The authors applied the distortion-sensitivity approach by measuring the processing of visually presented masked text in a condition with manipulated syntactic, lexical, and semantic cues and while using the Text Reception Threshold (George et al., 2007; Kramer, Zekveld, & Houtgast, 2009; Zekveld, George, Kramer, Goverts, & Houtgast, 2007) method. Two groups that differed in linguistic abilities were studied: 13 native and 10 non-native speakers of Dutch, all typically hearing university students. As expected, the non-native subjects showed substantially reduced performance. The results of the distortion-sensitivity approach yielded differentiated results on the use of specific linguistic cues in the 2 groups. The results show the potential value of the distortion-sensitivity approach in studying the role of linguistic abilities in speech understanding in noise of individuals with hearing impairment.

Toward protein-energy goal-oriented therapy?

Protein calorie malnutrition is a concern in critically ill patients. Prospective studies to define the ideal calorie/protein intake to administer not only to meet requirements but also to change outcome are lacking. Strack van Schijndel and colleagues have observed an improvement in survival when patients reach the calorie target according to indirect calorimetry and a protein intake of greater than 1.2 g/kg per day. Their prospective observational study sheds new light on this field.

Auditory masking using Gaussian-windowed stimuli

This study investigates auditory masking with Gaussian-windowed tones as target and masker stimuli. On the purpose of developing a time-frequency masking model, such stimuli minimize the time-frequency uncertainty. Also, as proposed by van Schijndel et al. (1999), they activate a single spectro-temporal observation window of the auditory system. The study presented here measured auditory masking with Gaussian-windowed stimuli with an ERB of 600 Hz and an effective duration of 9.6 ms. The masker was centered at 4 kHz. Its level was 60 dB SL. Four experiments were conducted. (1) Absolute thresholds for Gaussian-windowed and 300-ms-sinusoidal targets were measured and compared for 11 frequencies. (2) Masking patterns were obtained with targets of various frequency separations from the masker. (3) Forward masking functions with 4-kHz targets were measured at 5 temporal separations. (4) Forward masking was measured for different frequency separations between masker and target. These data are compared with those typically obtained with stimuli that are broader either in the frequency or time domain. A modelling attempt is made. A companying article on multiple masker additivity based on the present results is presented at the same conference (Laback et al.). Work partly supported by EGIDE (PAI Amadeus) and the ANR.

Decay-Accelerating Factor Ameliorates Systemic Autoimmune Disease in MRL/lpr Mice via Both Complement-Dependent and -Independent Mechanisms

Decay-accelerating factor (DAF) is a glycosylphosphatidylinositol-anchored membrane protein that restricts complement activation on autologous cells. Previous studies have established a significant protective activity of DAF in the MRL/lpr murine model of human systemic lupus erythematosus. To dissect the mechanism of protection by DAF in this disease model, we evaluated the effect of C3 gene ablation on disease development in MRL/lpr-Daf-1(-/-) mice. We found no significant difference in lymphadenopathy, splenomegaly, or anti-chromatin autoantibody titer between complement-sufficient and complement-deficient MRL/lpr-Daf-1(-/-) mice. On the other hand, complement deficiency strikingly reduced the incidence and severity of dermatitis in MRL/lpr-Daf-1(-/-) mice. To assess the contribution of DAF expression on lymphocytes versus local tissues in suppressing dermatitis, we generated BM chimeric mice between MRL/lpr-Daf-1(-/-) and MRL/lpr-Daf-1(+/+) mice. Compared with MRL/lpr-Daf-1(-/-) --> MRL/lpr-Daf-1(-/-) controls, MRL/lpr-Daf-1(-/-) --> MRL/lpr-Daf-1(+/+) chimeras developed significantly attenuated dermatitis, suggesting that the protective effect of DAF in suppressing dermatitis is primarily attributable to its local expression. We conclude that DAF works as a complement regulator in the skin to protect MRL/lpr mice from skin inflammation, whereas its inhibitory role in the induction phase of MRL/lpr autoimmunity is complement-independent. Together, these results reveal multiple mechanisms of action for DAF in ameliorating systemic autoimmunity.

National Procedures, Public Policy and EC Law. From Van Schijndel to Eco Swiss and Beyond

Abstract: The concept of public policy lies at the heart of national private (procedural) law. In the Community law, the European courts has dealt with public policy in a number of cases, most of which illustrate the problem of enforcement of EC law through national procedural rules and mechanisms. This article analyses the most important case law of the ECJ dealing with this issue, in particular hallmark cases like Van Schijndel and Eco Swiss). The authors argue that public policy as a complex phenomenon needs careful consideration when used in the context of EC law. The contribution elaborates on the foundations of the Community public policy as well as criteria for defining certain rules as rules of public policy suggesting that the fundamentality of the rule in question for Community legal order should be decisive as criterion.

Process design optimisation using embedded hybrid visualisation and data analysis techniques within a genetic algorithm optimisation framework

Process optimisation is a difficult task due to the non-linear, non-convex and often discontinuous nature of the mathematical models used. Although significant advances in deterministic methods have been made, stochastic procedures, specifically genetic algorithms, provide an attractive technology for solving these optimisation problems. However, genetic algorithms are not naturally suited to highly constrained problems. We propose a targeted genetic algorithm for process optimisation which is suitable for highly constrained problems. The genetic operators, crossover and mutation, are defined based on information gained about the feasible region and the behaviour of the objective function through the use of a data analysis procedure. The data analysis is based on a visual representation, the parallel co-ordinate system. A pattern matching algorithm, the Scan Circle Algorithm [K. Wang, A. Salhi, E.S. Fraga, Cluster identification using a parallel co-ordinate system for knowledge discovery and nonlinear optimization, in: J. Grievink, J. van Schijndel (Eds.), Proceedings of the 12th European Symposium on Computer-Aided Process Engineering, Computer-Aided Chemical Engineering, vol. 10, Elsevier, Amsterdam, 2002, pp. 1003–1008], is extended through the use of Learning Vector Quantization [T. Kohonen, Self-Organizing Maps, Springer-Verlag, Heidelberg, 1995] to identify, automatically, key features of the objective function and the search space. These features are used to target the genetic operators. Results from the application of the new targeted genetic algorithm to an oil stabilisation problem are presented, demonstrating the effective, efficient and robust nature of the implementation. The use of visualisation as the core of the data analysis step also provides a useful tool for explaining the results obtained by the optimisation procedure.

The Biology and Enzymology of Protein Tyrosine O-Sulfation

The Biology and Enzymology of Protein Tyrosine O-Sulfation

Optimal operation of a hospital power plant : van Schijndel, A. W. M. Energy and Buildings, 2002, 34, (10), 1055–1065

Optimal operation of a hospital power plant : van Schijndel, A. W. M. Energy and Buildings, 2002, 34, (10), 1055–1065

The mid-duration hump in the intensity-difference limen as a function of frequency: Further evidence for the frequency–time listening window of the human ear

It has been suggested that the ear has a frequency–time listening window and that the stimulus that occupies the fewest frequency–time windows, i.e., that which has the smallest product of effective bandwidth and effective duration, should result in the largest intensity-difference limen (DL) [Van Schijndel et al., J. Acoust. Soc. Am. 105 (1999)]. Van Schijndel et al. identified the Gaussian-shaped tone-pip as the optimal stimulus, obtaining DLs at 1 kHz and 4 kHz. The DLs were greatest for the tone-pips whose frequency–time window was one critical band wide and 4 cycles long in equivalent square duration D (envelope duration/ 3.19). Here, DLs for Gaussian-shaped 250-Hz tone-pips were obtained from 5 subjects for Ds of 1.25–22.57 ms at levels of 40, 50, 60, 70, 80, and 90 dB SPL. These data were combined with earlier results showing a mid-duration rise at 40–60 dB SPL for Gaussian-shaped tone-pips of 6.5 kHz, 2 kHz, and 500 Hz. The peak in the DL is sharp for 6.5 kHz but flattens as frequency drops, being replaced by a broad rise for 250 Hz. The highest DLs correspond to approximately 4 cycles in D, not far from the ringing duration calculated as the inverse of the critical bandwidth.

The intensity-difference limen for Gaussian-enveloped stimuli as a function of level: tones and broadband noise.

Van Schijndel et al. [J. Acoust. Soc. Am. 105, 3425-3435 (1999)] have proposed that the internal excitation evoked by an auditory stimulus is segmented into "windows" according to the stimulus spectrum and stimulus length. This "multiple looks" model accounts for the mid-duration hump they observed in plots of intensity-difference limens (DLs) versus pip duration for Gaussian-shaped 1- and 4-kHz tones, an effect replicated by Baer et al. [J. Acoust. Soc. Am. 106, 1907-1916 (1999)]. However, van Schijndel et al. and Baer et al. used few levels. A greater number of levels were used by Nizami (1999) for Gaussian-shaped 2-kHz tone-pips whose equivalent rectangular duration (D) was 1.25 ms. The DLs show the mid-level hump known for clicks [Raab and Taub, J. Acoust. Soc. Am. 46, 965-968 (1969)]. At some duration this pattern must become the "near-miss to Weber's law." To determine this duration, as well as the level-dependence of the mid-duration hump, DLs were established for Gaussian-shaped 2-kHz tone-pips of D = 1.25, 2.51, and 10.03 ms at levels of 30-90 dB SPL. The across-subject average DLs for the tone-pips rise up at mid-levels for D= 1.25 and D = 2.51 ms. The DLs for D=2.51 ms are larger, creating the mid-duration hump. At all durations, the new DLs are smaller at high levels than at low levels, consistent with the near-miss to Weber's law. DLs were also obtained here for Gaussian-shaped broadband-noise pips of D=0.63, 1.25, 2.51, 5.02, and 10.03 ms. The DLs for the noise-pip show a mid-level hump for all pip durations. The noise-pip DLs decrease as the pip lengthens, such that the plot of DL versus log duration shows a linear decline, with no mid-duration hump. Analysis of variance reveals that the mid-level hump coexists with the classical patterns of level-dependence, perhaps reflecting the existence of two level-encoding mechanisms, one that depends on firing-rates counted over single neurons and which is responsible for the classical patterns, and one that depends on the initial coordinated burst of neuronal spikes caused by rapid ramping, and which presumably causes the mid-level hump.

Detection and intensity discrimination of brief tones as a function of duration by hearing-impaired listeners

For normal listeners, difference limens for intensity (DLs) for Gaussian-shaped tone pulses are largest at medium pulse durations (corresponding to about five cycles of the tonal carrier) when the pedestals are 10 dB above threshold, either in quiet or in a pink noise background. One explanation for this is that worst performance occurs when the internal representation of the tone pulses is most compact in time and frequency, affording minimal opportunity for ‘multiple looks’ (Van Schijndel et al., J. Acoust. Soc. Am. 105 (1999) 3425–3435). However, the mid-duration worsening is largest for medium overall levels, suggesting an involvement of compression on the basilar membrane (BM), which is also greatest at medium levels (Baer et al., J. Acoust. Soc. Am. 106 (1999) 1907–1916). If this is so, the mid-duration worsening should be reduced when BM compression is reduced by outer hair cell damage. To test this, subjects with sensorineural hearing losses were tested using 1-kHz or 4-kHz Gaussian-shaped tone pulses, in quiet or in pink noise that raised thresholds by 10–20 dB. For subjects with mild losses, poorest performance was sometimes found for medium durations. For more severe losses, intensity DLs tended to improve monotonically or remain roughly constant with increasing duration. Performance overall tended to be better for subjects with greater hearing losses. The results are more consistent with an explanation based on BM compression than with an explanation based on multiple looks.

Intensity discrimination of brief Gaussian-windowed tones by hearing-impaired listeners

For normal listeners, intensity DLs for Gaussian-shaped tone pulses are largest at medium pulse durations when the pedestals are 10 dB above threshold, either in quiet or in a pink-noise background. One explanation is that worst performance occurs when the internal representation is most compact in time and frequency, affording minimal opportunity for multiple looks [N. H. van Schijndel, T. Houtgast, and J. Festen, J. Acoust. Soc. Am. 105, 3425–3435 (1999)]. However, the mid-duration worsening is largest for medium overall levels, suggesting an involvement of the compression on the basilar membrane (BM), which is also greatest at medium levels [T. Baer, B. C. J. Moore, and B. R. Glasberg, J. Acoust. Soc. Am. 106, 1907–1916 (1999)]. If so, the mid-duration worsening should be reduced when BM compression is reduced by outer hair cell damage. To test this, subjects with sensorineural losses were tested using 1-kHz or 4-kHz pulses, in quiet or in pink noise that raised thresholds by 10–20 dB. For subjects with mild losses, poorest performance was sometimes found for medium durations. For more severe losses, intensity DLs tended to improve monotonically or remain roughly constant with increasing duration. The results provide support for both multiple-look and BM-compression explanations. [Work supported by MRC.]

SYK Is Upstream of Phosphoinositide 3-Kinase in B Cell Receptor Signaling

We have recently demonstrated that the D3-phosphoinositide phosphatidylinositol 3,4,5-trisphosphate (PtdIns-3,4,5-P(3)) is critical for producing sustained calcium signals through its role in promoting the function of TEC family tyrosine kinases such as Bruton's tyrosine kinase. Although PtdIns-3,4,5-P(3) can potentially be synthesized by any of several types of phosphoinositide 3-kinases (PI3Ks), B cell receptor (BCR)-induced PtdIns-3,4,5-P(3) production is thought to occur primarily through the activation of the class Ia (p85/p110) PI3Ks. This process has been proposed to be mediated by an interaction between the Src family kinase LYN and the p85 subunit of PI3K and/or through p85 membrane recruitment mediated by CBL and/or CD19. However, calcium signaling and other PI3K-dependent signals are relatively preserved in a LYN kinase-deficient B lymphocyte cell line, suggesting that an alternative pathway for PI3K activation exists. As SYK/ZAP70 kinases are upstream from many BCR-initiated signaling events, we directly analyzed SYK-dependent accumulation of both PtdIns-3,4,5-P(3) and PtdIns-3,4-P(2) in B cell receptor signaling using both dominant negative and genetic knockout approaches. Both methods indicate that SYK is upstream of, and necessary for, a significant portion of BCR-induced PtdIns-3,4, 5-P(3) production. Whereas CD19 does not appear to be involved in this SYK-dependent pathway, the SYK substrate CBL is likely involved as the dominant negative SYK markedly attenuates CBL tyrosine phosphorylation and completely blocks the BCR-dependent association of CBL with p85 PI3K.

Human 70-kDa SHP-1L Differs from 68-kDa SHP-1 in Its C-terminal Structure and Catalytic Activity

Human 70-kDa SHP-1L Differs from 68-kDa SHP-1 in Its C-terminal Structure and Catalytic Activity